Abstract:In order to further study the adaptability and tolerance mechanism of Vaccinium dunalianum to drought stress, this study used potted V. dunalianum plants as test material to compare the effects of different days of drought stress on the physiological characteristics. The results showed that during different drought stress treatment periods, the chlorophyll content of V. dunalianum leaves increased first and then decreased, and reached the peak(0.62 mg/g) on the 7th day. The content of MDA, which represents the degree of membrane lipid peroxidation, kept increasing and reached the highest value of 24.22 μmol/g on the 28th day. With the prolongation of drought stress time, the Pro content of V. dunalianum leaves shows a trend of first increasing, then decreasing, and then increasing,which was significantly higher than that in CK group. SS content showed an upward trend, reached the peak on the28th day, which had significant difference with the CK group. With the extension of drought stress time, SOD activity of V. dunalianum leaves increased first and then decreased, while POD activity showed a trend of up-down-up.The results of this study indicated that V. dunalianum could resist drought damage by adjusting their osmotic adjustment substance content and antioxidant enzyme activity in the early stage of drought stress, while in the later stage,the damage of protective enzyme system and cell membrane was serious, which affected the normal growth of V. dunalianum plants.