Thanks mudassarkhan, your articles are really helpful to duplicate data between spreadsheets. But I'm sorry that I didn't make my question clear: what i want to copy between sheets is not only data, but also including images and charts  .

I have got some achievements using Interop by studing these refrences in MSDN:

http://msdn.microsoft.com/en-us/library/ms173186(VS.80).aspx
http://msdn.microsoft.com/en-us/library/microsoft.office.interop.excel._workbook.saveas(VS.80).aspx
http://msdn.microsoft.com/fr-fr/library/microsoft.office.interop.excel.workbooks.open(VS.80).aspx
http://msdn.microsoft.com/en-us/library/microsoft.office.interop.excel.worksheets.copy(VS.80).aspx

I must say Worksheets.Copy() is really a good way to meet my requirement because it does copies objects(including data, images and charts) from one works sheet to another. However, I found that some style is gone or wrong, for example, the background color is gone and some font color is changed in the destination excel file.

So does any guy know how to keep the original styles of a worksheet/workbook when they are being copied to another place?

Thanks a lot!