>I have try yuor suggestion, but it doesn't work.
>I found an workarounbd, that is #INCLUDE '\COMMOM30\INCLUDE\FRAMEWRK.H' in my subclass appincl.h
>
>As we know, .H file is only in "limited" scope. But after I added the .H file above, my program work ok. It will cause error again if I remove the line.

When you create a "regular" MM VFP application, the appincl.h file *does* have that same INCLUDE statement in it:

*-- Framework-specific constants
#INCLUDE '..\COMMON30\INCLUDE\FRAMEWRK.H'

It's acceptable to do the same in the appincl.h file you have created.

Regards,