Abstract: In order to confirm the pathogen of stored Lanzhou lily bulb rot disease,the pathogenicity of pure culture isolated from the samples of disease tissue was tested according to Koch's law,the pathogens were identified according to morphological characteristics and ITS sequence analysis,and biological characteristics were determined. The results showed that Lanzhou lily rot disease was caused by Aspergillus flavus and Rhizopus oryzae. The optimal growth condition of the two pathogens was not different. For the mycelia growth and sporulation of A. flavus and R. oryzae,the optimum medium were lily agar and lily dextrose agar,the optimum carbon source and nitrogen source were glucose and peptone separately,the optimum temperature was 25 ℃ and they could grow on the medium from p H5 to p H9. Light could improve mycelia growth and sporulation of A. flavus and R. oryzae.