Abstract: In order to evaluate the antibacterial effect of clove oil in a comprehensive and reasonable way, effects of clove oil with different concentrations on the growth of Penicillium expansum and the production of patulin were investigated in vitro and in vivo.The results showed that 26.0 μL / L clove oil had obvious inhibitory effects on spore germination, the growth of Penicillium expansum and the production of patulin in solid medium.However, treatment of clove oil at the same concentration promoted the production of patulin in liquid medium and in vivo unless improving the content of clove oil to 130 μL / L.This study indicated that the effect of clove oil on the production of patulin needed to be considered in order to obtain the antibacterial effect and food safety.