Abstract: In this study, data of four maize varieties such as indexes of leaf area, photosynthetic potential，net assimilating rate and accumulation of dry matter were com pared. These four maize varieties were Jindan 35, Hengfeng 1, Nongda 3138 and JIndan 34.The results showed: in the whole breeding periods, change of indexes of leaf area, photosynthetic potential of four varieties possessed the trend that prior rose and then gradually dropped. In different breeding periods, Jindan 35's data such as indexes of leaf area, photosynthetic potential were higher than those of other three varieties; the changes of net assimilating rate of the four varieties were prior decline then rise and then gradual descending. In terms of net assimilating rate, Hengfeng 1's was highest and Jindan35 's lowest. The order of accumulation of dry matter was Hengfeng 1, then Jndan 35, Nongda 3138, the last one was Jindan 34.