Sour rot is one of the most important grape diseases in China.It occurs seriously in main grape-producing region, causing great production loss and lower quality of grape.The studies on etiology and pathogenesis of this disease are ambiguous and controversial at present due to the complexity of grape sour rot.In view of the above situation, isolation, biological characteristics and pathogenesis of the pathogen (s) causing grape sour rot were conducted.In this study, 25 strains of microbes were isolated from ten samples of grape sour rot by the tissue isolation method.