For example : This is my Album structure

Main Album Graphic
Sub Album 1 | Wallpaper
Sub Album 2 |__ 800x600
Sub Album 2 |__ 1024x768
Sub Album 1 | Scan
Sub Album 1 |_____ Artbook

I try to display all images from Graphic album and its subalbum in index page, which function can do this?

You mean you want to display them inside the albums AND as a collection of single images on the first page?

That's right Can anyone help me?

There is no direct function for this, you would have to write one. You could take the print_album_menu plugin as as start.

This has been done before by someone. Please try I forum search (I can't remember the thread though).