RadRichTextBox doesn't support most used Chinese IMEs - QQ Pinyin and Sogou Pinyin.
With our latest Q3 2014 release we introduced an API that allows implementing custom support for different IMEs. We believe that this approach is more flexible than supporting some specific IMEs only, since it provides the freedom to add support for any desired IME. We have prepared an SDK example showing a custom implementation of Caret extension. Here is the link to the SDK Repository: https://github.com/telerik/xaml-sdk/tree/master/RichTextBox/CustomCaret Just for your information the feature is released with a known issue for caret positioning and loosing focus, but we are already investigating the cause. I hope that we will soon release a fix for that. Do not hesitate to contact us if you experience any issues or if you have any suggestions for improvement. We would appreciate any feedback. Regards, The Telerik Team
Tried QQ wubi in windows 8 , is still not supported.