Abstract: In order to explore stomatal conductance model for rice seedlings under far-red light irradiation environment and improve simulation accuracy of this model, observation experiments were conducted on gas exchange parameters and stomatal characteristics of two varieties of rice seedlings under far-red light irradiation environment．Ball-Berry linear stomatal conductance semi empirical model（BB model）and optimal stomatal behavior theoretical model（USO model）were selected to set stomatal conductance of rice seedlings from macro and micro perspectives．Responses of stomatal conductance of rice seedlings under far-red light irradiation environment were studied．Stomatal conductance model of light controlled environment was fitted and stomatal conductance model of far-red light environment was modified based on corrected photosynthetic rate．Revised model was evaluated using correlation coefficient（R²）, standard error（RMSE）, and mean absolute error（MAE）．Results showed that simulation accuracy of modified BB model and USO model has significantly improved by 15.3% and 8%, respectively．It could provide theoretical basis for calculation of light controlled agricultural water carbon cycle and research on biological water-saving．