Parental involvement and students' academic achievement are closely related.This study collected the information of 3245 students from grade 3 to grade 6 in 68 primary schools in Xianyang and Weinan prefecture in Shaanxi province.The purpose of this paper is to analyze the association between parental involvement and students’ academic achievement by Ordinary Least Squares (OLS)regression analysis.Results show that there is a positive relationship between parents communicating with their children concerning their studies and students' academic achievement.The relationship between parental involvement and students' achievement is more significant for non-left-behind children than left-behind children.Findings，to some extent，will provide feasible solutions for how to improve the academic achievement of primary students in western China.