This article is to study the occurrence pattern and the species of gentiana spot blotch pathogen. The gentiana spot blotch was investigated in Shannxi. Gentiana spot blotch pathogen were isolated and cultured in the persent study using the dissociation method, were observed in microsope and then were identified. The observed results showed that the pathogen could develop hyphae on PDA plate and develop many conidia. The conidium was clubbed,ellipsoid and ovaliform, and was easy to come off. The top of the conidium prolonged to be beaked, becoming chain, with transverse and longitudinal septa, which was slightly branched. The hyphal wall was thin. The hyphae was septata branched and can develop conidia. The results showed that: It was easy to make the disease epidemic in higher temperature, humidity and daylight. The pathogen was identified as Deuteromycotina subphylum, Hgphomycetes class, Hyphomycetales order, Dematiaceae family,Alternaria Nees ex Wallr species.
