Effects of salicylic acid (SA) on senescence of detached tea plant (Camellia sinensis) leaves were investigated. by two-group experimental design using different concentration gradient separately with solution treatment of SA, one group at 0, 100, 200, 300, 400, 500 mg/L and another at 0, 50, 100, 150, 200 mg/L. Results demonstrated that certain concentration of SA was able to slow down efficiently the senescence process of detached leaves of tea plant, but the detached leaves displayed different degrees of injured phenomenon with concentrations of SA above 200 mg/L. However, the detached leaves were maintained normal and decreases in activity of SOD, contents of chlorophyll, contents of soluble protein, and accumulation of MDA were alleviated by SA at the concentration of 50, 100, 150 mg/L, among which the 100 mg/L had the best effect.