I have found that even if not use other fonts but just replace the system default application font Sans with Nimbus Sans L, the Chinese characters are acceptable already. Please look at the screen shot.
This one is good enough for me. :-)
Because the characters are in the same size now.
If I set the default font in application to Kaiti, some other english characters are ugly.
My method might only be helpful to those people who are new to Mandrake Llinux 10 and are going to view chinese characters.