Abstract:To identify the species of Alternaria, the pathogen that causes black spot on Ya-pears during storage, the isolated Alternaria from the sporulation pattern, conidia characters and molecular biology were examined. With morphological and molecular biological study on 188 isolated strains of Alternaria, three species are identified, namely Alternaria alternata, A.tenuissima, and A.infectoria, accounting for 41.0%, 54.8%, and 1.6% of the total strains respectively. Based on ITS and gpd data, it is evidently distinguished between the large-spored Alternaria spp. and between the large- and the small-spored Alternaria spp.; it is not distinguished among the samall-spored Alternaria spp.