Abstract: The effects of natural plants extracts against banana postharvest disease Colletotrichum musae was evaluated. The antifungal activity of 0～40 μL TTO(tea tree oil) and its main components (Terpinenol-4, α-Terpineol, γ-Terpinene and 1,8-Cineole) against colony growth of C. musae in vitro and their effects on disease intensity and defense–related enzymes of banana fruits inoculated with C. musae were determined at 25°C and 75% relative humidity. Results showed that fumigation of TTO, Terpinenol-4 and α-Terpineol could significantly inhibit C. musae growth in vitro. In addition, the antifungal activity of TTO and its main components could be greatly enhanced with higher levels. Compared with non-treated fruits, 1.25 g/L TTO fumigation reduced lesion diameter of inoculated banana fruits, but less than 0.32 g/L Terpinenol-4 or α-Terpineol. Moreover. 1.25 g/L TTO fumigation induced significant increase in peroxidase(POD), and phenylalanine ammonia-lyase(PAL), but decreased polyphenoloxidase(PPO) activity. The preliminary study suggests that TTO fumigation is feasible on fresh-keeping and increasing of disease resistance in postharvest banana fruits, meanwhile, Terpinenol-4 and α-Terpineol are primary antifungal activities of TTO.