Abstract:Asparagus stem blight is a worldwide devastating disease. To identify accurately its pathogen and to make it clear the differences of isolates from different provinces, the identification was carried out using morphology examination and net BLAST of rDNA ITS sequences, the differences in both biological characteristics and ITS sequences were compared, and the phylogenetic relationship was analyzed. The result revealed that the pathogen of asparagus stem blight was Phomopsis asparagi. The growth speed of isolates from Hainan was the fastest, with an average diameter of 8.5 centimeter after 5 days’ culture. After 14 days’ culture, the colony of isolates from Jiangxi grew pale green from white, those from the other provinces grew gray white from white, and that from Hainan displayed concentric wheel pattern. The number of pycnidia of isolates from Fujian was the highest with an average account of 60/dish. There existed differential base in the 1-238bp and 298-591bp fragments of ITS sequences in isolates from 5 provinces, of which more differential bases appeared in the isolates from Hebei. Isolates from the 5 provinces clustered 2 groups, of which the isolates from Hebei clustered a single group and the ones from the other provinces clustered another group, fungi from the same genus clustered together, and P.asparagi behaved nearer in phylogenetic relationship with P.phyllanthicola.