I use redhat 3 now , and have installed a redhat 5 , I want to migrate it to this new server .

I have successfully migrated the user to new server , but I just found the the PATH setting ( echo $PATH) of root in both servers are different, it seems something is missing in migration , ( only root user have problem , other users is ok ) I have already copy all user home directory to new server include /root directory , /etc/profile but still not , can advise what is wrong ?

thanks.

Assuming you mean RHEL3 => RHEL5, they are 2 Major versions apart... I'd expect some differences.
If you are absolutely sure you need a certain dir in root's PATH, then add it to their .bash_profile.
I certainly wouldn't have copied over /etc/profile.

Did you copy over root's .profile and/or .bashrc/.bash_profile?

And AGAIN, have you contacted Red Hat support???? You continue to post questions regarding RHEL in a corporate environment, but have yet to take this advice, or even acknowledge you got it. If you're using RHEL, you're paying for support and access to the Red Hat network. If you're NOT paying, then you SHOULD NOT BE USING IT. All you are managing to do then, is to put servers into production, that have no chance of being updated/patched, and you will wind up with buggy servers with security problems. Access to the Red Hat network is pay-for, and addresses that. Otherwise, load CentOS.