Hi,

When Excel main window is maximazed,
by Double-clicking Application's Menubar(the upper blue part), the window
size is changed.
If possible, I want to disable the window-size change.
Is it possible?

Maybe this question is about win32api.
But I don't know where the win32api-newsgroup is.

Thanks in advance.

If the workbook window is maximized it will enlarge when Excel is maximized
(I think that's what you're saying).

So you have to "restore" the workbook window, and protect it:

ActiveWindow.WindowState = xlNormal
ActiveWorkbook.Protect Windows:=True

--
Jim Rech
Excel MVP