Based on experiments of biochenllcal changes in peanut plants(Arach is hypogaes)before and after rust(Puccinia arachidis)infection,the relationships between multiple biochemical com- pounds and rust resistance was analyho by using quantitative correlation method.Aller rust infection,changes of inducing sugars in peanut plants are highbcorrelated to disease resist-ance.Some free amino aclds,such as serine,leucine.methionine,isoleucine and arginine,are correlated to rust asistance at certain periods after infhoon.In healthy peanut plants,the ac- tivity of polyphenol oxidase,the amounts of threonine,serine,isoleucine and phenylalanine were highly correlated to disease resistance.