The History Channel has a plethora of topics about China and its history. The website offers a reasonably lengthy summary of the topic (Boxer Rebellion), audio, videos, and speeches about the topic. This website is great for a review of the topic or to use its audio-visual resources during your lessons.
Vu, this is a great source. I have used the History Channel website in the past to have students explore topics on iPads. Each page has a wonderful interactive layout with copious amounts of related material that the students almost always love to engage in. I have not used the website to explore Asian-related historical events so I found your post incredibly helpful for future lessons that will center around Asian historical events.