Workbook wb = new HSSFWorkbook();
Sheet sheet = wb.createSheet("new sheet");

Row row = sheet.createRow((short) 1);
Cell cell = row.createCell((short) 1);
cell.setCellValue("This is a test of merging");

sheet.addMergedRegion(new CellRangeAddress(
        1, //first row (0-based)
        1, //last row  (0-based)
        1, //first column (0-based)
        2  //last column  (0-based)
));

//Create a Workbook.
Workbook wbk = new Workbook();

//Create a Worksheet and get the first sheet.
Worksheet worksheet = wbk.getWorksheets().get(0);

//Create a Cells object to fetch all the cells.
Cells cells = worksheet.getCells();

//Merge some Cells (C6:E7) into a single C6 Cell.
cells.merge(5,2,2,3);

//Input data into C6 Cell.
worksheet.getCells().get(5,2).setValue("This is a test of merging");

//Save the Workbook.
wbk.save("merge_Aspose.xls");