路径系数是相关系数间因果关系的一种统计量。它不仅不受度量单位和自变量变异程度的影响，去除了度量各自变数的相对重要性，而且能区分自变量对因变量的直接作用和间接作用,因而得到广泛应用。推导了路径分析数学公式的全过程，参照便于计算机程序实现的矩阵算法，使用Python语言运演了路径分析，并对分析结果的参数使用条件作出了说明。

Path coefficient is a statistic of causality between correlation coefficients. It is not only affected by the variation degree of measurement units and independent variables, but also can distinguish the direct and indirect effects of independent variables on dependent variables, so it has been widely used. This paper focuses on the whole process of deriving the mathematical formula of pathanalysis. Referring to the matrix algorithm which is convenient for computer program implementation, the path analysis is run in Python language. The parameters and application conditions of the analysis results are explained.