The temperature at which the highest photosynthetic rate of grapevine varieties was obtained was at a range of 20-30℃, though the optimum temperature varied depending on the varieties. The photosynthetic rate obviously declined at lower or higher temperature than that. The evapotranspiration (ET) rates of the varieties generally increased as temperature increased, and the rate was the highest between 30-35℃. stomatal conductivity, CO_2 concentration inside cell spaces and water-use efficiency reached the maximum at 15-20℃. Thereafter, they decreased as temperature increased. In the group of tetraploid varieties of ‘Kyoho’ line, the photosynthetically optimum temperature zone varied depending on the varieties. The differences in leaf morphology between tetraploids and diploids was large. The photosynthetic rate of varieties used as semidwarf rootstocks had a tendency to be low. Concerning cultivars, there were 1% level of significant difference among stomatal conductivity, ET rate and CO_2 concentration in cell spaces under any temperature conditions in the assimilatory spaces. At the temperature higher than 25℃, 1% level of significance differences among photosynthetic rate, ET rate and stomatal conductivity were also observed, and the coefficient correlations were high as the temperature was high.