diff --git a/QXlsx/header/xlsxdocument.h b/QXlsx/header/xlsxdocument.h
index 85ad347..688612e 100644
--- a/QXlsx/header/xlsxdocument.h
+++ b/QXlsx/header/xlsxdocument.h
@@ -118,6 +118,8 @@ public:
     bool saveAs(const QString &xlsXname) const;
     bool saveAs(QIODevice *device) const;
 
+    bool saveAsCsv(const QString mainCSVFileName) const;
+
     // copy style from one xlsx file to other
     static bool copyStyle(const QString &from, const QString &to);
 
diff --git a/QXlsx/header/xlsxdocument_p.h b/QXlsx/header/xlsxdocument_p.h
index 978df5e..5638dfe 100644
--- a/QXlsx/header/xlsxdocument_p.h
+++ b/QXlsx/header/xlsxdocument_p.h
@@ -23,6 +23,8 @@ public:
     bool loadPackage(QIODevice *device);
     bool savePackage(QIODevice *device) const;
 
+    bool saveCsv(const QString mainCSVFileName) const;
+
     // copy style from one xlsx file to other
     static bool copyStyle(const QString &from, const QString &to);
 
diff --git a/QXlsx/source/xlsxdocument.cpp b/QXlsx/source/xlsxdocument.cpp
index 9b58675..d2b1d03 100644
--- a/QXlsx/source/xlsxdocument.cpp
+++ b/QXlsx/source/xlsxdocument.cpp
@@ -470,6 +470,111 @@ bool DocumentPrivate::savePackage(QIODevice *device) const
     return true;
 }
 
+//
+// j2doll/csv branch
+//
+// Save from XLSX to CSV
+bool DocumentPrivate::saveCsv(QString mainCSVFileName) const
+{
+    Q_Q(const Document);
+
+    int sheetIndexNumber = 0;
+    foreach (QString curretnSheetName, q->sheetNames())
+    {
+
+        QXlsx::AbstractSheet *currentSheet = q->sheet(curretnSheetName);
+
+        if (NULL == currentSheet)
+        {
+            continue;
+        }
+
+        // get full cells of sheet
+        int maxRow = -1;
+        int maxCol = -1;
+
+        currentSheet->workbook()->setActiveSheet(sheetIndexNumber);
+
+        Worksheet *wsheet = (Worksheet *) currentSheet->workbook()->activeSheet();
+        if (NULL == wsheet)
+        {
+            continue;
+        }
+
+        QString strSheetName = wsheet->sheetName();                                // sheet name
+
+        QVector<CellLocation> clList = wsheet->getFullCells(&maxRow, &maxCol);
+
+        QVector<QVector<QString>> cellValues;
+        for (int rc = 0; rc < maxRow; rc++)
+        {
+            QVector<QString> tempValue;
+
+            for (int cc = 0; cc < maxCol; cc++)
+            {
+                tempValue.push_back(QString(""));
+            }
+
+            cellValues.push_back(tempValue);
+        }
+
+        for (int ic = 0; ic < clList.size(); ++ic)
+        {
+            CellLocation cl = clList.at(ic);
+
+            int row = cl.row - 1;
+            int col = cl.col - 1;
+
+            std::shared_ptr<Cell> ptrCell = cl.cell; // cell pointer
+            QVariant var = ptrCell->value();
+            QString str = var.toString();
+
+            cellValues[row][col] = str;
+        }
+
+        // TODO:
+        //  (1) save as csv file name (using { mainCSVFileName + strSheetName })
+
+        QString csvFileName = mainCSVFileName + QString("_") + strSheetName + QString(".csv");
+        QFile csvFile(csvFileName);
+        if ( ! csvFile.open( QIODevice::WriteOnly ) )
+        {
+            continue;
+        }
+
+        //  (2) save sheet values
+        //     such as  A,,B,,,,C,,,D,,
+
+        for (int rc = 0; rc < maxRow; rc++)
+        {
+            for (int cc = 0; cc < maxCol; cc++)
+            {
+
+                QString cellData = cellValues[rc][cc];
+
+                if ( cellData.size() >= 0  )
+                {
+                    csvFile.write( cellData.toUtf8() ); // cell data
+                }
+
+                csvFile.write( QString(",").toLatin1() ); // delimeter
+            }
+
+            csvFile.write( QString("\n").toLatin1() ); // CR
+
+            csvFile.flush();
+        }
+
+        // file.flush();
+
+        csvFile.close();
+
+    } // foreach (QString curretnSheetName, q->sheetNames()) ...
+
+
+    return true;
+}
+
 bool DocumentPrivate::copyStyle(const QString &from, const QString &to)
 {
     // create a temp file because the zip writer cannot modify already existing zips
@@ -1278,6 +1383,16 @@ bool Document::saveAs(QIODevice *device) const
     return d->savePackage(device);
 }
 
+
+bool Document::saveAsCsv(const QString mainCSVFileName) const
+{
+    Q_D(const Document);
+
+    return d->saveCsv( mainCSVFileName );
+}
+
+
+
 bool Document::isLoadPackage() const
 {
     Q_D(const Document);
diff --git a/csv/csv.pro b/csv/csv.pro
new file mode 100644
index 0000000..2162eeb
--- /dev/null
+++ b/csv/csv.pro
@@ -0,0 +1,45 @@
+# csv.pro
+
+TARGET = csv
+TEMPLATE = app
+
+QT += core
+QT += gui
+
+CONFIG += console
+CONFIG -= app_bundle
+
+# NOTE: You can fix value of QXlsx path of source code.
+#  QXLSX_PARENTPATH=./
+#  QXLSX_HEADERPATH=./header/
+#  QXLSX_SOURCEPATH=./source/
+include(../QXlsx/QXlsx.pri)
+
+##########################################################################
+# The following define makes your compiler emit warnings if you use
+# any feature of Qt which as been marked deprecated (the exact warnings
+# depend on your compiler). Please consult the documentation of the
+# deprecated API in order to know how to port your code away from it.
+DEFINES += QT_DEPRECATED_WARNINGS
+
+##########################################################################
+# You can also make your code fail to compile if you use deprecated APIs.
+# In order to do so, uncomment the following line.
+# You can also select to disable deprecated APIs only up to a certain
+# version of Qt.
+#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000   
+# disables all the APIs deprecated before Qt 6.0.0
+
+##########################################################################
+# source code
+
+SOURCES += \
+main.cpp 
+
+# RESOURCES += \
+# test.qrc
+
+RESOURCES += \
+    test.qrc
+
+
diff --git a/csv/main.cpp b/csv/main.cpp
new file mode 100644
index 0000000..6a53629
--- /dev/null
+++ b/csv/main.cpp
@@ -0,0 +1,44 @@
+// main.cpp
+
+#include <iostream>
+// using namespace std;
+
+#include <QCoreApplication>
+#include <QDebug>
+#include <QVariant>
+#include <QVector>
+#include <QtCore>
+#include <QtGlobal>
+
+#include "xlsxcellrange.h"
+#include "xlsxchart.h"
+#include "xlsxchartsheet.h"
+#include "xlsxdocument.h"
+#include "xlsxrichstring.h"
+#include "xlsxworkbook.h"
+
+
+int main(int argc, char *argv[])
+{
+    QCoreApplication app(argc, argv);
+
+
+    {
+        using namespace QXlsx;
+
+        QString xlsxFileName = ":/test.xlsx";
+        QXlsx::Document xlsxDoc(xlsxFileName);
+        if (!xlsxDoc.isLoadPackage()) {
+            return 0; // failed to load
+        }
+
+        QString csvFileName = "hello.csv";
+        if ( xlsxDoc.saveAsCsv(csvFileName) ){
+            qDebug() << "save as csv file";
+        }
+
+    }
+
+     	
+    return 0;
+}
diff --git a/csv/test.qrc b/csv/test.qrc
new file mode 100644
index 0000000..55f7b89
--- /dev/null
+++ b/csv/test.qrc
@@ -0,0 +1,6 @@
+<!DOCTYPE RCC>
+<RCC version="1.0">
+<qresource>
+    <file>test.xlsx</file>
+</qresource>
+</RCC>
diff --git a/csv/test.xlsx b/csv/test.xlsx
new file mode 100644
index 0000000..6f1b3a8
Binary files /dev/null and b/csv/test.xlsx differ