This study used fifteen-year-old ninth-grade students from rural areas of five provinces in western China as samples to carry out research on the relationship between the socioeconomic status of Chinese families and student academic performance. Based on parents' educational background, occupation, family economic conditions, and other factors, the family socioeconomic status index was calculated. This paper sets out to explore the gradient changing relationship between student academic performance and family socioeconomic status. (Contains 4 tables and 4 notes.)