The study presents a conceptual platform in the effort to study stomatal reaction of corn plants under different water status. The model is developed by combining a two dimensional soil model (2DSOIL) and a corn model (Maizesim). Transport of water through the soil-plant-atmosphere continuum is simulated. Different mechanisms are implemented in the model to simulate the reaction of stomatal conductance to radiation level, temperature, vapor pressure deficit, soil moisture level, soil temperature etc. The applicability of different mechanisms is examined with data collected in the corn field and SPAR (soil-plant-atmosphere research) chambers.