In order to compare the differences in eco-physiological characteristics between male and female plants and to further understand the ecological adaptability of Rhus typhina Linn., the diurnal variations of photosynthetic parameters and the fluorescence characteristics of male and female plants were determined respectively with photosynthesis system (CIRAS-2) and portable chlorophyll fluorometer (PAM-2100). The relative chlorophyll content was determined with relative chlorophyll content determination (SPAD-502). The length and width of leaf were measured with ruler. The results showed that the SPAD of male was greater than that of the female by 9.6%. The diurnal variation of net photosynthetic rate of male and female plants showed obvious midday depression. The daily mean of net photosynthetic rate of male plant was greater than that of the female by 22.7%, and there was significant difference between them. The daily means of transpiration rate was greater than that of the female by 18.5%. The water use efficiency of male plant was 2.3 μmol·mmol-1, which was greater than that of the female by 21.7%, and there was significant differences between them. The diurnal variations of light use efficiency of male and female plants were similar but the light use efficiency of male was higher. The Fv/Fm of male plant was higher than 0.76 and was higher than that of the female during the measurement period. The female reduced to the lowest which was 0.69 at 13:00 p.m. Both the leaf length and width of female were smaller, but the ratio of length and width was greater compared with the male, and there was significant difference between them. The net photosynthetic rate, water use efficiency and light use efficiency of male were higher than that of female, and it had stronger adaptability to environment.