Abstract: The feasibility of genome-wide association study（GWAS） on the basic theory of powdery mildew resistance of thin-skinned muskmelon was studied by using resequencing method in 118 germplasm resources of thin-skinned muskmelon from Northeast and East China, in order to provide reference for enriching breeding materials for powdery mildew resistance of thin-skinned muskmelon.The results showed that a total of 4 460 133 SNP loci with high quality were obtained, and 61 excellent alleles related to powdery mildew were screened by the two models.Combined with functional annotation, DPH3 antibody protein, PPR protein, flavonol synthase, methylesterase and DMR6 oxygenase-l et.It was mainly involved in metabolic processes such as biosynthesis, amino acid metabolism, signaling pathway conduction, RNA degradation and DNA repair.The CsTLP gene on chromosome 7 played an important role in cucumber downy mildew resistance; EFM1 on chromosome 1 could be a good candidate gene for stress response mechanism research and stress resistance breeding.