Abstract: Several basic characteristics of photosynthesis of three oak species in the nursery stock period have been studied by gas exchange method in this paper. The results show 1. For Quercus mongolica, the light compensation point, light saturation point, and light-saturated rate of photosynthesis are relatively high, while its quantum efficiency is relatively low, indicating that it can use solar radiation with high intensity efficiently, but the efficiency of using weak light is low. Such photosynthetic characteristics are opposite in Q. acutissima. Both the light saturation point and light-saturated rate of photosynthesis are relatively hight, at the same time the quantum efficiency is also hight in Q. liaotungensis, but light compenation point is low. Therefore, it can use both high and low light energy efficiently. 2. It is provd that the exponential equation P_n=P_(max)·(1-e^-aI/P_(max)))-R is the most rational for sinmulating photosynthetic response to light intensity in three oak species. 3. The differences of photosynthetic characteristics between Q. acutissima and Q. liaotugensis at various periods of growing season, and the influence of temperature on photosynthetic characteristics in three oak species have been also investigated.

Key words: Three oak species, Photosynthesis, Sesponse model, At avrious periods of growing season, Temperature influence