Abstract: This study aimed to test the inhibition of potassium sorbate and sodium benzoate on the growth of poisonous Aspergillus flavus, which provided reference data for preventing peanut and other corps becoming mildewed in preservation process.Using Aspergillus flavus spores as experimental materials, which were cultured in solid culture medium. The germination number was counted, colony size was measured, colony color, the morphological characteristics of mycelium and Spore F1 were observed, respectively. At last, the data got from above, were analyzed with SPSS16.0 statistical software.The results showed that both preservatives had significant inhibition ( p≤0.05) on the growth of Aspergillus flavus when the mass concentration was higher than or equal to 1.0g /L.Furthermore, sodium benzoate had modification effects at 1.0g /L.While, given a concentration, potassium sorbate had a better inhibition effect than sodium benzoate.In brief, potassium sorbate ( ≥1.0g /L) is a more secure, more economical, more convenient and more effective fungistat to Aspergillus flavus.