Abstract: To study the inhibitory effects of natural phenolic food spices on Aspergillus flavus, seven phenolic spices including 4-propylphenol, 2-isopropylphenol, 2-propylphenol, thymol, ethyl maltol, tea polyphenol and maltol were investigated for their antifungal efficacy on Aspergillus flavus by the contact testing with sorbic acid as a positive control.Furthermore, the inhibitory effect of different concentrations of 4-propylphenol, which showed the best antifungal activity among the selected compounds, was further studied by contact testing and fumigation bioassay on the growth of Aspergillus flavus mycelium, and the minimum inhibitory concentration(MIC)and minimum fungicidal concentration(MFC)were determined after incubation in a constant temperature incubator at(28±2)℃ for 6 days.Moreover, 4-propylphenol was further evaluated as an antifungal fumigant for its practical applicability to control Aspergillus flavus infection on stored peanut seeds, including the fumigation inhibitory and fungicidal effects of different concentrations of 4-propylphenol on the growth of Aspergillus flavus.The results showed that most of the phenolic spices exerted varied inhibitory effect on Aspergillus flavus through the screening with contact testing method.Among these compounds, 4-propylphenol had the best inhibitory effect, and the inhibition rate was about twice as sorbic acid, indicating that its antifungal efficacy was significantly better than the common food preservative sorbic acid.The results also showed that the inhibitory effect of 4-propylphenol on the growth of Aspergillus flavus was dose-dependent, and the MIC of 4-propylphenol on Aspergillus flavus under the conditions of contact testing and fumigation bioassay were 0.35 mg/mL and 0.04 mg/mL, respectively, which indicated that 4-propylphenol could inhibit the growth of Aspergillus flavus at a lower concentration by the fumigation bioassay method with a stronger inhibitory effect.Nevertheless, in comparison with the fumigation bioassay method, a higher concentration of 4-propylphenol under the contact condition was required to achieve the same inhibitory effect under the fumigation condition.Different concentrations of 4-propylphenol showed fumigant inhibitory effects on Aspergillus flavus on stored peanuts in a dose-dependent manner.The growth of Aspergillus flavus on stored peanuts was completely inhibited when the fumigation concentration of 4-propylphenol is higher than 1.1 mg/mL(MIC), while Aspergillus flavus on stored peanuts could be sterilized when the fumigation concentration was higher than 1.7 mg/mL(MFC)with the fumigation treatment for 24 h, indicating that 4-propylphenol has high potential as an antifungal fumigant for protecting peanut seeds from contamination of Aspergillus flavus during storage.These results revealed that 4-propylphenol has promising potential to be developed into a new, safe and environmentally friendly antifungal fumigant to control Aspergillus flavus infection on stored peanut seeds.Besides, the present research has a promoting significance to provide a basis and reference for the development of other new green, safe and efficient natural food preservatives.