In order to study the effects of salicylic acid （SA） treatment on heat tolerance of blueberry （ Vaccinium spp. ） , two cultivars V3 and Misty of blueberry treated by 0. 1 mmol/L SA were subjected to heat stress trentment, and their physiological indexes were measured. Heat stress with 42 ℃ led to blueberry leaf yellowing and wilting, in manual climatic chamber. However, 0. 1 mmol/L SA treatment could alleviate effectively the above symptom. Proline contents declined with SA treatment compared with heat stress control （control 2）. The biggest drop occurred at 96 h, decrease of V3 and Misty were 10.47% and 30. 11%, respectively; relative electroconduetibilities declined with SA treatment compared with control 2. The biggest drop appeared at 96 h. Decrease of V3 was 22.52% , and the decrease of Misty were 18.5% at 24 h, 20.5% at 96 h. SA alleviated the damage of cell membrane integrity via decreasing the contents of Malonic dialdehyde （MDA）. The MDA of Misty decreased more significantly than that of V3 during heat stress. SA was able to stimulate the antioxidant system via increasing Superoxide dismutase （SOD） activity for improving the heat resistances of blueberry. Compared with the control, SOD activity of the two cultivars at 96 h increased more significantly than that at 24 h during heat stress. Thus, SA was able to stimulate SOD activity and regulate the osmotic balance for improving the heat resistances of blueberry, as a result of alleviating the damage of the cell membrane, decreasing the chlorophyll degradation and protecting the physiological function of the normal protein. Misty was more sensitive than V3 to heat stress and SA treatment.