Abstract: Taking green walnut as the test material, pathogenic bacteria were isolated using tissue isolation method, and their pathogenicity was determined based on Koch′s rule.The morphological characteristics of the pathogenic bacteria and rDNA-ITS sequence analysis were combined to identify the types of pathogenic bacteria, in order to provide reference for the prevention and control measures of post harvest rot disease in green walnut.The results showed that the post harvest diseases of green walnut were anthracnose and black spot, and five dominant pathogenic bacteria were isolated.Based on the morphology of the pathogens and rDNA-ITS sequence analysis, it was confirmed that HT73 and HT55 were Colletotrichum siamense,HT12 was Colletotrichum gloeosporioides,HL35 was Fusarium sp, and HP92 was Botryospaeria dothidea.This study identified the main pathogenic bacteria causing green walnut rot disease, which could provide a basis for effectively preventing postharvest rot disease in green walnuts.