Abstract: The purpose of the study was to explore gender differences in physiology and protective enzyme activity of dioecious plant species at different temperatures. Seed of the dioecious climbing herb Humulus scandens were planted in pots; at the 1-2 true leaf stage seedlings were moved to an incubator with three temperature settings (15, 20, 25 ℃) based on the mean temperature of the area of seed provenance origin. Photosynthesis, metabolism, antioxidant enzyme activity and cell membrane integrity were measured. The effect of temperature on photosynthesis, respiration and resistance of H. scandens to temperature was determined. Temperature significantly affected leaf chlorophyll content, light-saturated photosynthetic rate (P_n) and biomass which significantly decreased with decreasing temperature. The P_n of female plants was always significantly higher than that of males (P<0.05). Soluble sugar (SS) and pyruvic acid (PA) contents and nitrate reductase activity (NRA) were also affected by temperature change (P<0.05); SS content was lower but NRA higher with decreasing temperature. Sugar metabolism and respiration rate of males was significantly higher than females (P<0.05), while nitrogen metabolism was not influenced by gender. Temperature affected metabolism more than gender. Temperature significant affected superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) (P<0.05) activity which increased with decreasing temperature; SOD and POD activity in females plants were significant higher than those of males (P<0.05) but CAT activity was not influenced by gender. The effect of temperature on cell membrane traits was greater than that of gender. H₂O₂, malondialdehyde (MDA), proline (Pro) and soluble protein (SP) content also increased significantly with decreasing temperature. Higher H₂O₂ and SP but lower MDA and Pro were observed in male compared to female plants. Our results indicated that gender differences in photosynthesis, respiration, antioxidant enzyme system and cell membrane integrity response to low temperature were of less importance than differences due to temperature.