i try t set up a variable environment but i have problem.

as root i do "name variable"=name variable; export name variable;
PATH=.....

but when i do reboot the variables is not there.i don't know how to save a variable.
Do yoy have any suggestions?

Depends on what shell you using. The variable that is being changed needs to be included in the startup "script" that the shell uses.

If appending, you can do this: PATH=$PATH:/foo/bar , but if you are prefixing do this: PATH=/foo/barPATH .

Anyway, the following is a quick break down of what might need to be touched:

csh
.login
.cshrc

sh/ksh
.profile

bash
.bash_profile
.bash_login
.profile

Definitely check your shell docmentation for details though.