Abstract: Licorice root rot plants collected from May to July 2020 were used as test materials.Tissue separation technology was used to isolate pathogenic bacteria and combined with morphological characteristics and molecular biology techniques to determine the pathogen species of licorice root rot.Effects of various media, light, pH, temperature, carbon and nitrogen sources on biological characterisation of pathogenic bacteria were studied, in order to clarify the species of root rot pathogens and the optimum culture conditions of the pathogens that affect the growth of licorice in Xinjiang.The results showed that 96 fungal strains isolated by tissue separation method produced the same onset symptoms as those in the field according to Koch′s rule, and it was clear that the pathogens of root rot in Xinjiang were Fusarium oxysporum,Fusarium solani and Fusarium verticillioides.The optimal culture condition was PDA medium with natural pH and placed in a constant temperature incubator with alternating light and darkness for 12 hours at 25-28 ℃.