[Objective] This paper identifies the fine-grained preferences of online bookstore users, aiming to optimize the personalized book recommendation service. [Methods] First, we conducted sentiment analysis of the book features through readers' comments, which indicated their preferences. Then, we calculated the books' sentiment scores based on the readers' comments. Finally, the user preferences matrix and the sentiment scores matrix were matched to personalize the book recommendation. [Results] We retrieved the needed data from Amazon's book...