A strain which could produce a high concentration of jasmonic acid was screened from more than 100 molds in nature and preserved in the laboratory. It was named as Lasiodiplodia iranensis DWH-2. Optimized fermentation medium composition contained sucrose 50 g/L, NaNO3 4.5 g/L, KH2PO4 2 g/L, KCl 0.4 g/L, MgSO4·7H2O 6 g/L, FeSO4·7H2O 0.9 g/L, corn pulp 1.5g/L, trace element 10 ml/L, soybean oil 10g/L, and its initial pH value was 5.5. The culture media volume and culture temperature was optimized to 100 mL/500 mL and 28 ℃, respectively. Under these conditions, the yield of jasmonic acid could reach 1.543 g/L after 7 days.