diff --git a/examples/xlsx/hello/main.cpp b/examples/xlsx/hello/main.cpp
index dd6997e..3830893 100755
--- a/examples/xlsx/hello/main.cpp
+++ b/examples/xlsx/hello/main.cpp
@@ -31,7 +31,7 @@ int main()
     xlsx.write(1, 1, 200);
     xlsx.write(2, 1, 300);
     xlsx.write(3, 1, 400);
-    xlsx.write(4, 1, "=SUM(B1:B4)");
+//    xlsx.write(4, 1, "=SUM(B1:B4)");
 
     xlsx.saveAs(DATA_PATH"Test.xlsx");
     return 0;
diff --git a/src/xlsx/xlsxpackage.cpp b/src/xlsx/xlsxpackage.cpp
index 085aaa7..a3da444 100644
--- a/src/xlsx/xlsxpackage.cpp
+++ b/src/xlsx/xlsxpackage.cpp
@@ -283,11 +283,7 @@ void Package::writeDocPropsCoreFile(ZipWriter &zipWriter)
 
 void Package::writeSharedStringsFile(ZipWriter &zipWriter)
 {
-    QByteArray data;
-    QBuffer buffer(&data);
-    buffer.open(QIODevice::WriteOnly);
-    m_workbook->sharedStrings()->saveToXmlFile(&buffer);
-    zipWriter.addFile(QStringLiteral("xl/sharedStrings.xml"), data);
+    zipWriter.addFile(QStringLiteral("xl/sharedStrings.xml"), m_workbook->sharedStrings()->saveToXmlData());
 }
 
 void Package::writeStylesFiles(ZipWriter &zipWriter)
diff --git a/src/xlsx/xlsxsharedstrings.cpp b/src/xlsx/xlsxsharedstrings.cpp
index cfbc38c..d463278 100755
--- a/src/xlsx/xlsxsharedstrings.cpp
+++ b/src/xlsx/xlsxsharedstrings.cpp
@@ -24,15 +24,16 @@
 ****************************************************************************/
 #include "xlsxsharedstrings_p.h"
 #include "xlsxxmlwriter_p.h"
+#include "xlsxxmlreader_p.h"
 #include <QDir>
 #include <QFile>
 #include <QRegularExpression>
 #include <QDebug>
+#include <QBuffer>
 
 namespace QXlsx {
 
-SharedStrings::SharedStrings(QObject *parent) :
-    QObject(parent)
+SharedStrings::SharedStrings()
 {
     m_stringCount = 0;
 }
@@ -46,23 +47,49 @@ int SharedStrings::addSharedString(const QString &string)
 {
     m_stringCount += 1;
 
-    if (m_stringTable.contains(string))
-        return m_stringTable[string];
+    if (m_stringTable.contains(string)) {
+        XlsxSharedStringInfo &item = m_stringTable[string];
+        item.count += 1;
+        return item.index;
+    }
 
     int index = m_stringTable.size();
-    m_stringTable[string] = index;
+    m_stringTable[string] = XlsxSharedStringInfo(index);
     m_stringList.append(string);
     return index;
 }
 
+void SharedStrings::removeSharedString(const QString &string)
+{
+    if (!m_stringTable.contains(string))
+        return;
+
+    m_stringCount -= 1;
+
+    XlsxSharedStringInfo &item = m_stringTable[string];
+    item.count -= 1;
+
+    if (item.count <= 0) {
+        for (int i=item.index+1; i<m_stringList.size(); ++i)
+            m_stringTable[m_stringList[i]].index -= 1;
+
+        m_stringList.removeAt(item.index);
+        m_stringTable.remove(string);
+    }
+}
+
 int SharedStrings::getSharedStringIndex(const QString &string) const
 {
-    return m_stringTable[string];
+    if (m_stringTable.contains(string))
+        return m_stringTable[string].index;
+    return -1;
 }
 
 QString SharedStrings::getSharedString(int index) const
 {
-    return m_stringList[index];
+    if (index < m_stringList.count() && index >= 0)
+        return m_stringList[index];
+    return QString();
 }
 
 QStringList SharedStrings::getSharedStrings() const
@@ -99,4 +126,56 @@ void SharedStrings::saveToXmlFile(QIODevice *device) const
     writer.writeEndDocument();
 }
 
+QByteArray SharedStrings::saveToXmlData() const
+{
+    QByteArray data;
+    QBuffer buffer(&data);
+    buffer.open(QIODevice::WriteOnly);
+    saveToXmlFile(&buffer);
+
+    return data;
+}
+
+QSharedPointer<SharedStrings> SharedStrings::loadFromXmlFile(QIODevice *device)
+{
+    QSharedPointer<SharedStrings> sst(new SharedStrings);
+
+    XmlStreamReader reader(device);
+    int count = 0;
+    while(!reader.atEnd()) {
+         QXmlStreamReader::TokenType token = reader.readNext();
+         if (token == QXmlStreamReader::StartElement) {
+             if (reader.name() == QLatin1String("sst")) {
+                 QXmlStreamAttributes attributes = reader.attributes();
+                 count = attributes.value(QLatin1String("uniqueCount")).toInt();
+             } else if (reader.name() == QLatin1String("si")) {
+                 if (reader.readNextStartElement()) {
+                     if (reader.name() == QLatin1String("t")) {
+                         QXmlStreamAttributes attributes = reader.attributes();
+                         QString string = reader.readElementText();
+
+                         sst->m_stringTable[string] = XlsxSharedStringInfo(sst->m_stringTable.size(), 0);
+                         sst->m_stringList.append(string);
+                     }
+                 }
+             }
+         }
+    }
+
+    if (sst->m_stringTable.size() != count) {
+        qDebug("Error: Shared string count");
+    }
+
+    return sst;
+}
+
+QSharedPointer<SharedStrings> SharedStrings::loadFromXmlData(const QByteArray &data)
+{
+    QBuffer buffer;
+    buffer.setData(data);
+    buffer.open(QIODevice::ReadOnly);
+
+    return loadFromXmlFile(&buffer);
+}
+
 } //namespace
diff --git a/src/xlsx/xlsxsharedstrings_p.h b/src/xlsx/xlsxsharedstrings_p.h
index 8d92707..7d4b5cf 100755
--- a/src/xlsx/xlsxsharedstrings_p.h
+++ b/src/xlsx/xlsxsharedstrings_p.h
@@ -25,31 +25,47 @@
 #ifndef XLSXSHAREDSTRINGS_H
 #define XLSXSHAREDSTRINGS_H
 
-#include <QObject>
+#include "xlsxglobal.h"
 #include <QHash>
 #include <QStringList>
+#include <QSharedPointer>
 
 class QIODevice;
 
 namespace QXlsx {
 
-class SharedStrings : public QObject
+class XlsxSharedStringInfo
 {
-    Q_OBJECT
 public:
-    explicit SharedStrings(QObject *parent = 0);
+    XlsxSharedStringInfo(int index=0, int count = 1) :
+        index(index), count(count)
+    {
+    }
+
+    int index;
+    int count;
+};
+
+class XLSX_AUTOTEST_EXPORT SharedStrings
+{
+public:
+    SharedStrings();
     int count() const;
     
-public slots:
     int addSharedString(const QString &string);
+    void removeSharedString(const QString &string);
+
     int getSharedStringIndex(const QString &string) const;
     QString getSharedString(int index) const;
     QStringList getSharedStrings() const;
 
     void saveToXmlFile(QIODevice *device) const;
+    QByteArray saveToXmlData() const;
+    static QSharedPointer<SharedStrings> loadFromXmlFile(QIODevice *device);
+    static QSharedPointer<SharedStrings> loadFromXmlData(const QByteArray &data);
 
 private:
-    QHash<QString, int> m_stringTable; //for fast lookup
+    QHash<QString, XlsxSharedStringInfo> m_stringTable; //for fast lookup
     QStringList m_stringList;
     int m_stringCount;
 };
diff --git a/src/xlsx/xlsxworkbook.cpp b/src/xlsx/xlsxworkbook.cpp
index 2be82f3..ed6cd07 100755
--- a/src/xlsx/xlsxworkbook.cpp
+++ b/src/xlsx/xlsxworkbook.cpp
@@ -40,7 +40,7 @@ namespace QXlsx {
 WorkbookPrivate::WorkbookPrivate(Workbook *q) :
     q_ptr(q)
 {
-    sharedStrings = new SharedStrings(q);
+    sharedStrings = QSharedPointer<SharedStrings> (new SharedStrings);
     styles = new Styles(q);
 
     x_window = 240;
@@ -176,7 +176,7 @@ QList<Worksheet *> Workbook::worksheets() const
 SharedStrings *Workbook::sharedStrings()
 {
     Q_D(Workbook);
-    return d->sharedStrings;
+    return d->sharedStrings.data();
 }
 
 Styles *Workbook::styles()
diff --git a/src/xlsx/xlsxworkbook_p.h b/src/xlsx/xlsxworkbook_p.h
index 2405ea1..6d81d96 100644
--- a/src/xlsx/xlsxworkbook_p.h
+++ b/src/xlsx/xlsxworkbook_p.h
@@ -25,6 +25,7 @@
 #ifndef XLSXWORKBOOK_P_H
 #define XLSXWORKBOOK_P_H
 #include "xlsxworkbook.h"
+#include <QSharedPointer>
 
 namespace QXlsx {
 
@@ -36,7 +37,7 @@ public:
 
     Workbook *q_ptr;
 
-    SharedStrings *sharedStrings;
+    QSharedPointer<SharedStrings> sharedStrings;
     QList<Worksheet *> worksheets;
     Styles *styles;
     QList<QImage> images;
diff --git a/tests/auto/auto.pro b/tests/auto/auto.pro
index b8a58f4..b86ac2b 100644
--- a/tests/auto/auto.pro
+++ b/tests/auto/auto.pro
@@ -6,4 +6,5 @@ SUBDIRS=\
     relationships \
     propscore \
     propsapp \
-    readdocument
+    readdocument \
+    sharedstrings
diff --git a/tests/auto/sharedstrings/sharedstrings.pro b/tests/auto/sharedstrings/sharedstrings.pro
new file mode 100644
index 0000000..10503b2
--- /dev/null
+++ b/tests/auto/sharedstrings/sharedstrings.pro
@@ -0,0 +1,13 @@
+QT       += testlib xlsx xlsx-private
+CONFIG += testcase
+DEFINES += XLSX_TEST
+
+TARGET = tst_sharedstringstest
+CONFIG   += console
+CONFIG   -= app_bundle
+
+TEMPLATE = app
+
+
+SOURCES += tst_sharedstringstest.cpp
+DEFINES += SRCDIR=\\\"$$PWD/\\\"
diff --git a/tests/auto/sharedstrings/tst_sharedstringstest.cpp b/tests/auto/sharedstrings/tst_sharedstringstest.cpp
new file mode 100644
index 0000000..ac3aa79
--- /dev/null
+++ b/tests/auto/sharedstrings/tst_sharedstringstest.cpp
@@ -0,0 +1,103 @@
+#include "private/xlsxsharedstrings_p.h"
+#include <QString>
+#include <QtTest>
+#include <QXmlStreamReader>
+
+class SharedStringsTest : public QObject
+{
+    Q_OBJECT
+
+public:
+    SharedStringsTest();
+
+private Q_SLOTS:
+    void testAddSharedString();
+    void testRemoveSharedString();
+
+    void testLoadXmlData();
+
+};
+
+SharedStringsTest::SharedStringsTest()
+{
+}
+
+void SharedStringsTest::testAddSharedString()
+{
+    QXlsx::SharedStrings sst;
+    sst.addSharedString("Hello Qt!");
+    sst.addSharedString("Xlsx Writer");
+    sst.addSharedString("Hello World");
+    sst.addSharedString("Hello Qt!");
+
+    QByteArray xmlData = sst.saveToXmlData();
+    QXmlStreamReader reader(xmlData);
+
+    int count = 0;
+    int uniqueCount = 0;
+    while(!reader.atEnd()) {
+        QXmlStreamReader::TokenType token = reader.readNext();
+        if (token == QXmlStreamReader::StartElement) {
+            if (reader.name() == QLatin1String("sst")) {
+                QXmlStreamAttributes attributes = reader.attributes();
+                count = attributes.value("count").toInt();
+                uniqueCount = attributes.value("uniqueCount").toInt();
+            }
+        }
+    }
+
+    QCOMPARE(count, 4);
+    QCOMPARE(uniqueCount, 3);
+}
+
+void SharedStringsTest::testRemoveSharedString()
+{
+    QXlsx::SharedStrings sst;
+    sst.addSharedString("Hello Qt!");
+    sst.addSharedString("Xlsx Writer");
+    sst.addSharedString("Hello World");
+    sst.addSharedString("Hello Qt!");
+    sst.addSharedString("Hello Qt!");
+
+    sst.removeSharedString("Hello World");
+    sst.removeSharedString("Hello Qt!");
+    sst.removeSharedString("Non exists");
+
+    QByteArray xmlData = sst.saveToXmlData();
+    QXmlStreamReader reader(xmlData);
+
+    int count = 0;
+    int uniqueCount = 0;
+    while(!reader.atEnd()) {
+        QXmlStreamReader::TokenType token = reader.readNext();
+        if (token == QXmlStreamReader::StartElement) {
+            if (reader.name() == QLatin1String("sst")) {
+                QXmlStreamAttributes attributes = reader.attributes();
+                count = attributes.value("count").toInt();
+                uniqueCount = attributes.value("uniqueCount").toInt();
+            }
+        }
+    }
+
+    QCOMPARE(count, 3);
+    QCOMPARE(uniqueCount, 2);
+}
+
+void SharedStringsTest::testLoadXmlData()
+{
+    QXlsx::SharedStrings sst;
+    sst.addSharedString("Hello Qt!");
+    sst.addSharedString("Xlsx Writer");
+    sst.addSharedString("Hello World");
+    sst.addSharedString("Hello Qt!");
+    QByteArray xmlData = sst.saveToXmlData();
+
+    QSharedPointer<QXlsx::SharedStrings> sst2 = QXlsx::SharedStrings::loadFromXmlData(xmlData);
+
+    QCOMPARE(sst2->getSharedString(0), QStringLiteral("Hello Qt!"));
+    QCOMPARE(sst2->getSharedString(2), QStringLiteral("Hello World"));
+}
+
+QTEST_APPLESS_MAIN(SharedStringsTest)
+
+#include "tst_sharedstringstest.moc"