Abstract: Aflatoxin is well known with considerable adverse effects including the induction of genetic mutation, liver cancer and the suppression of the immune system on human and animal. Control of aflatoxin contamination is a worldwide problem. Mechanism involved in the aflatoxin-production inhibition by Lentinus edodes cellulose derivatives GPX was investigated. The results showed that inhibition rates of toxin production by 10 and 50μg/mL of the GPX were 70% and 95%, respectively. More GPX (100, 250, 500, 750, 1000μg/mL) gave the rise to complete inhibition of toxin production. Without high antioxidant activity in vitro, GPX could modify oxidative stress in A. flavus. In addation, GPX was found to promote premature fusion of vesicles and formation of vacuole in A. flavus, which was proved association with the inhibition of aflatoxin production.