The effects of light intensity and air temperature on net-photosynthesis of intact plants have been studied in a number of species and cultivars of legumes under controlled environment conditions. Obtained data were processed by the methods of regression analysis and models were constructed, which determine quantitative combinations of light and temperature, which ensure optimum and maximum net-photosynthesis intensity in plants. Revealed plant requirements to environment conditions can be considered as an ecological characteristic of studied plant species and varieties at particular developmental phase.