Abstract: Dioscorea stem rot disease is a serious disease infected dioscorea in Hainan recently. At present, it has been broken out in Haikou and Lingao of Hainan, and caused serious economic losses to the dioscorea production in Hainan. In order to understand its biological characteristics, and to provide references for prevention and control of this disease, the method of mycelium growth rate was used to determine the influence of medium, temperature, pH value and illumination on mycelium growth. Also, the influence of moisture and nutrient on spore germination was assayed. The results showed that the most suitable culture medium was PDA and optimum temperature was 25. The temperature of the mycelium growth ranged from 10 to 35. And lethal temperature was 50益for 10 min or 55益for 5 min. The optimal pH value was 7.0. The pH value of mycelium growth ranged from 5 to 10. Dim light conditions was the best lighting condition, and the best relative humidity was 100% for spore germination, solution composition had little effect on spore germination.