To optimize the fermentation-extraction process of the antioxidant of an endophytic fungus J8 from forsythia, the single-factor experimental and Plackett-Burman method were contributed to identify the most notable factors, then the central composite design of the response surface analysis(RSA) was used to fit the optimal combination. The optimum conditions were achieved as following, ammonium acetate =5.855 g/L,pH=7.82,solid-liquid ratio =1∶9.35. The desired value of the scavenging rate of ABTS+· free radical was 93.31%.For the actual experiment,as pH fixed at 7.8 and other factors as the same mentioned above,the scavenging rate reached 90.23%,which is similar to the desired value. The result provides the basic information about the further separation and purification of the antioxidants originated from an endophytic fungus J8 from forsythia.

forsythia; endophytic fungus; RSM; antioxidant