Abstract: In this paper,analysis was made of the walnut in Xiaba Township of Xuanhan County,Sichuan Province.Its disease symptom was observed and the kind of pathogen was identified in the laboratory.The dynamic changes of susceptibility rate and susceptible index were recorded on the surface of walnut nuts and leaves.Selected five kinds of fungicides were sprayed on the walnut.The results showed that the pathogen which causes walnut disease mainly was walnut anthracnose and its increasing speed on the nuts was faster than that on the leaves.The susceptibility rate and susceptible index on the surface of walnut nuts and leaves which were sprayed by 95% prochloraz were obviously lower than others.So 95% prochloraz was the best drug to prevent the walnut anthracnose.