中文摘要：

利用图论的方法,讨论了余因子系的性质,分析了余因子系的等价定义,给出了几种重要的等价形式.并利用树的特殊结构,给出了余因子系的树形表示,为引入多项式系各种形式的结式矩阵做了理论准备.

英文摘要：

　This paper,based on graph theories,investigates properties of the cofactor system of univariate polynomials and derive several equivalent definitions for a cofactor system.Furthermore,by means of the special structure of a tree,it presents tree-form representations for cofactor systems.The results in this paper should become theoretical preparations for introducing kinds of resultant matrices of polynomial system.