“Hello” doesn’t support Chinese, as once Niki has talked with me about it. Also I checked forum of Hello about it, and found many Chinese Hello User requested it.
Just now find a way to post Chinese in hello instead of be displayed with “???”, here is the way:
go to 在线字符转换工具, type the Chinese you want to display in the box “需转换内容”, and click “转换”, then copy the characters in “转换后的内容” to Hello and publish.
This method is also useful to elsewhere without Chinese supported, like Orkut and some other foreign forums.