Abstract: Two popular textbooks from China and America are chosen to analysis，and the comparative index system concluding the breadth and depth dimensions is built. The main conclusion is that the breadth and depth of knowledge of the textbook in China is lower than the United States ones，but students feel the textbook of China more difficult due to its highly demand of abstract mathematics. This model can be used for both qualitative and quantitative analysis，and also it can be used well as the tools for the comparison of international textbooks.

Key words: difficulty of the textbook, university physics, textbook comparison