Abstract: 【Objective】 This project aims to isolate an anthrax strain from alfalfa with the symptoms of anthracnose,which would be slightly different from the previously reported Colletotrichum trifolii and C.americae borealis in morphology in order to clarify the pathogenicity,taxonomic status and biological characteristics of this strain through a series of studies. 【Methods】 Anthrax strain was obtained by tissue isolation,and its pathogenicity was proved by Koch's rule and morphological observation combined with PCR amplification of polygene fragments was used to identify the pathogenic bacteria.Meanwhile,the effects of different culture media,carbon source,nitrogen source,temperature,pH value and light on the colony growth of anthrax strain were determined. 【Results】 A new pathogenic anthrax strain was isolated from alfalfa,and identified as Colletotrichum liriopes.The strain could grow under the conditions of 5-35℃ and pH 4-11,and most of the test medium,nitrogen source and carbon source conditions. 【Conclusion】 C.liriopes can infect alfalfa and cause anthracnose.The optimum growth temperature of C.liriopes is 28℃,the optimum nitrogen source and carbon source are yeast and soluble starch respectively,the optimum pH is 7,the lethal temperature of mycelium is 61℃,and the alternation of light and dark for 12 h is favorable to the growth of the colony.