Abstract: This study aimed to investigate the inhibitory effectiveness of carvacrol treatment on the mycelial growth,colony morphology and microstructure of Alternaria alternata and its control effect for Goji berry black mold during the postharvest storage. Furthermore,the effect of carvacrol treatment on peroxidase(POD)and phenylalanine ammonia lyase(PAL)activities in Goji berry fruit were studied. The results showed that carvacrol treatment significantly inhibited the spore germination and mycelial growth of A. alternata and the effectiveness was dose-dependent. Through treated with 8 μL/L carvacrol,the inhibition rates of mycelial growth and spore germination reached to 80.81% and 57.17%,respectively. Less mycelial,rough surfaces,uniform thickness and distorted cell were observed after treatment with 8 μL/L carvacrol by scanning electron microscopy(SEM). Meanwhile,carvacrol treatment not only resulted in lower disease incidence on inoculated Goji berry with A. alternata,but also enhanced the activities of POD and PAL and prevented disease development. These results suggested that carvacrol,as a safe preservative alternative to synthesis fungicide,might have potential application for postharvest disease control.