After ten hours of searching, finally I find the easiest way to get Chinese language support (both display and input) for AT&T BB8310 users.
1. Download the "BlackBerry Handheld Software v188.8.131.522 (Chinese, Japanese, and Korean)" at blackberry official site: https://www.blackberry.com/Downloads...e1AT4eAuWPyg**
(please note that the last two star symbols should be included)
There are two softwares available after you chose BB8310. The first is "Multilanguage" and the second is "Chinese, Japanese and Korean". Remeber: the second is the one you need!!!
2. Uninstall your current Desktop Manager.
3. Install the downloaded "BlackBerry Handheld Software v184.108.40.2062 (Chinese, Japanese, and Korean)" .
Now, you can view and input Chinese on your BB!!!
(Met a small problem, but too sleepy to sovle it. Although everything is working fine on the handheld, the Desktop Manager and Media Manager dispeared from my laptop after the process is completed. Even if I reinstalled the downloaded one and chose to "repair", they are still not available on my laptop. I can see RIM in C:\program files\common files, but not in the directory of C:\program files. I'm wondering whether uninstalling current Desktop Manager caused this problem.)
Anyone find a solution, please kindly feed back.
Anyway, it is good to view and input Chinese on my BB!!!
Hope this message is useful to you.