Please read lxde blog for detail.
http://blog.lxde.org/?p=118
It’s well known and well documented that our session manager LXSession Lite suppport the autostart freedesktop.org specs. However, autostart spec is a term for developers and it’s meaningless for our end users. Basically, it provides a way to automatically start some applications after login.
Now this can (partially) be configured through a simple GUI - LXSession Edit.
You can turn on some disabled gnome applications in LXDE with this handy tool.
Also, window manager used in LXDE can be changed with this tool, too (Only lxsession lite is supported, not the deprecated lxsession).
Currently adding and removing application from this startup list is not yet available, but it will be support in the next release.
The package is available here for testing: https://sourceforge.net/projects/lxde/
Testers and packagers are wanted!!