Abstract:Pepino (Solanum muricatum Ait.)seedlings were treated at 5─35℃ in growth chamber at light intensity of 100 umol m-2s-1. The young fully expanded leaves were excised after 3 days of treatment for a comparison of the temperature response of several phsiological characteristics.Higer photosynthetic rates appeared at temperature ranging from 15℃ to 30℃-.Photosynthetic rates was found at 20℃ which was associated with the highest rate of photosynthetic electron transport, photochemical efficiency of PS Ⅱ and quantum yield of PS Ⅱ electron transport, and it is also the case for chlorophyll content, but with the lowest permeability of cell membrane. These physiological parameters were obviously decreased at low temperature 5─10℃ and high temperature 35℃. The extent of the decrease was increased with prologation of treated time. The electrolyte leakage of cell membrane of leaves was reduced after eliminating from 5℃ treatment and transfering toroom temperature (15─20℃).