Glomerella leaf spot of apple (GLSA) caused by Colletotrichum gloeosporioides has become a major apple disease in the world. Considering the pathogenicicty differentiation of the pathogen isolated from different origins and ascertaining the apple germplasm resistance to GLSA, will be of great value to resistance breeding of apple, rational distribution of varieties and disease management. The pathogenicity differentiation of seventy-nine strains isolated from the different origins was studied by pathogenicity test in vitro. Significant pathogenicity difference differentination was detected in C. gloeosporioides, and the high virulent strains occupied a higher proportion. In addition, three-hundred and twenty-seven apple germplasms response to GLSA were evaluated by inoculated detached leaves, and one-hundred and sixty-six highly resistant germplasms, six moderately resistant germplasms, twenty-two moderately susceptible germplasms, and one-hundred and thirty-nine highly susceptible germplasms were screened respectively. The results showed that there are abundant resistant germplasms in apple. Based on the classify system of apple, this study indicated that resistant germplasms were distributed in each apple cultivar groups, in particularly Fuji and Jonathan cultivar groups.