The aflatoxinsB1（AFB1）in agricultural products was treated by low temperature radio frequency plasma and the degradation rate of AFB1 was analyzed by HPLC. The results showed that the effect of plasma treatment on degradation of AFB1 in agricultural products was significant. The degradation rate of AFB1 in peanut and corn reached to 88.3% and 92.2% respectively, by plasma treatment of 150 W for 500 s. AFB1 could be degraded more completely with transmit power and radiation time increasing. There was considerable difference in the degradation of AFB1 with different particle size of poisonous products under the same plasma conditions. The degradation rate of AFB1 in granular mixed peanut and corn sample were lower than that in powder.