What are the controversial issues in China? What is the specific land area?

There are some controversial points, namely:

Mohe, Huma, Heihe, Xunke, Jiayin, Lubei and Fuyuan.

It is basically a territorial dispute between Xinjiang and neighboring countries.

Finally, I'll tell you the actual territorial area of China now: 9.48 million square kilometers (excluding territorial waters and 89,000 square kilometers of Indian-occupied southern Tibet), which I found in the National Geographic Center.