sx Wu,
How did you access your GRASS from your PC? just through telnet? if it is the
case, you won't be able to open any graphics windows using d.mon, although you
can run GRASS. You have to install an Xserver onto your PC. in the Xserver
environment, you will get everything almost exactly the same as you are running
SUN console.
Xserver is within LAN Workplace Pro, which is coming along with NT server. talk
to your network administrator about it.
Good luck,
Houxiang