Both of them are good, and I heard that they are adapted versions of the same book. Moreover, both of them introduced many important concepts and theorems in the subsequent courses, which enriched the content of the book and increased the difficulty. The theorems in the book are all proofs, which are different from many textbooks in China at present. Those textbooks omit some difficult proofs, such as the second proof of L'H?pital's law. Generally speaking, the content and examples are very rich. There are a lot of examples and solutions in Xu Senlin's book, and the topics are divided into three levels. Beginners should try their best to complete the exercises of the first level, but there is one exception to the first question in each section, because the first question contains all the basic knowledge recently, but it is difficult. The content arrangement of Chang Gengzhe and Shi Jihuai is slightly reasonable, but it seems that the richness of examples and exercises is a bit inferior to that of Xu Senlin. However, there are many examples of Xu Senlin. It's up to you ... to master the theorem, its source and its use in the learning process. ...