thank for the information! I should more consider about what you said

Thank both of you!

For GecT
I change the maya file to the .ma file

and I just installed a Notepad text editor from internet

But I am not familiar with text editor

I still kind of try to...

Thank for replying me so fast :D
Yeah I tried the way u provides.
The mesh exported to other Maya file successfully.
But application was still crashed by I switching view point in the new file.
...

I was modeling motorbike
As I almost finish the modeling and started to work on detail part of element.
Maya was crashed ( and there is screen that show “maya application file has stopped working”)...