In this study,the effects of β-pinene on spore germination,tube elongation and mycelial growth of Penicillium italicum were assessed,and the effects of β-pinene on cell wall chitin distribution,active oxygen metabolism,acid excretion capacity and ergosterol contents of mycelia were analyzed.The effects of sorbitol,cholesterol and cysteine as protective agents on spore germination of P. italicum incubated with β-pinene were further evaluated.The results showed that β-pinene had strong antifungal activity against P. italicum in a dose dependent manner,as exhibited by spore germination and mycelium growth inhibition at the concentration ranging from 0.087 to 0.696 mg/mL.β-Pinene incubation also altered the distribution of chitin in cell wall,promoted the accumulation of reactive oxygen species (ROS),and significantly inhibited glucose-induced reduction in external pH of the mycelia.Addition of cholesterol as alternative of ergosterol,sorbitol as osmotic regulator,or cysteine as active oxygen scavenger could effectively promote the spore germination and tube elongation of the pathogen incubated with β-pinene at 0.348 mg/mL.These results revealed that the antifungal activity of β-pinene against P. italicum was related to the damage of cell wall structure,promotion of ROS accumulation and the inhibition of ergosterol increase in membrane.