Intercropping is a popular cropping system in high鄄yielding production of food and feed in the world, which is more productive than monocropping because of the intensive utilization of natural resources, such as sunlight, heat, water and fertilizer. As a component crop in most intercropping systems, maize can be intercropped with a variety of crops, such as common bean, faba bean, soybean and peanut, showing an important role, and an obvious intercropping yield advantage. Maize 椰 peanut intercropping as an important cultivation pattern expanded rapidly in Sichuan Province and Huang Huai Hai Plain, China. We found maize椰peanut intercropping enhanced the efficient utilization of strong sunlight by maize and weak sunlight by peanut, thus leading to intercropping advantages. To elucidate the photosynthetic mechanism of intercropping yield advantage of maize, that is, whether the better utilization of strong sunlight results from higher absorption and transmission of sunlight or enhanced photosynthetic CO 2 assimilation, a field experiment was conducted to investigate the effects of maize 椰 peanut intercropping on the characters of response curves of Pn to PFD and to CO 2 , fluorescence, and chlorophyll content and component of intercropped maize function leaves, dry matter accumulation and