I have installed Telnet server on my CentOs Server.
and set disable = no
a in xinted.d folder and reset xinted.
so telnet is started.
When I telnet to server,it will get login and password but I can't login into it by any username or password.
I tried root and root password too,but it will not work to.
where is the problem?
Why use telnet? It's an old, old, very insecure technology.
Use OpenSSH instead - it's much more secure, offers much more functionality (tunneling, file copy, key authentication to name a few), and comes by default with nearly every linux distro out there.
root is typically prevented from telnet access, because it is very bad security. If you want to remote in as root, you should use ssh. Really, you should not remote in as root, anyway. Create an ordinary user account, log in as that, and, if necessary, use "sudo" or "su".
That said, look at this document:
http://www.idevelopment.info/data/Unix/Linux/LINUX_TelnetFTPAsRoot.shtml