In this paper,3 kg/m~2 biochar was added into soil for studying the effect of biochar on growth and photosynthesis of eggplant. The result shows that biochar may promote plant height and stem diameter of eggplant,increase chlorophyll content,enhance the photosynthetic,transpiration rates and stomatal conductance,reduce the concentration of carbon dioxide between cells. Adding biochar into soil can promote the growth and photosynthesis of eggplant.