I am looking for a type of wireless lan usb adapter, which used in perating System Red Hat Linux 7.2.
Can someone recommend some types of wireless lan usb adapter to me?
Thanks for anyone's help.

One that's either linux supported by the manufacturer or one that's on this list:
http://ndiswrapper.sourceforge.net/wiki/index.php/List

Thank you for reply.
I have tried "ndiswrapper-0.11", but it didn't work well, in addition, it confindes to some certain types of wireless adapter and some types of operaing system .
I prefer the "usb wireless adapter" that "red hat linux 7.2" is supported by the manufacturer, if possible.

Hello Woodpecker,

That is why you are asking for a recommendation is it not? Wireless networking in linux is a bit of a mess at the moment. Your best option is to locate a usb adapter at the link darkleaf gave and use ndiswrapper with that. I'm sorry to hear it didnt work well but then you are using quite an old OS there which in itself is from before the days of widespread wireless use. Its your best option at the moment. Otherwise you may want to investigate linuxant's driverloader.

http://www.linuxant.com/driverloader/

That however, is an option you have to pay for.
However a quick look at the HCL at this site shows

Linksys WUSB11 v2.6

might be your baby but honestly I'd upgrade my OS first to save me some hassle.
Regards
Chris

You'll need a pretty new kernel as well, at least 2.4 to run wireless.