The study was carried out to investigate the photosynthetic characteristics in different leaf positions of maize for three maize varieties under five density levels. The results showed that the photosynthetic rates of the three maize varieties were higher in upper leaves than in lower leaves, the difference of photosynthetic rates for the upper leaves of ear-leaf were higher than the lower ones of them. Photosynthetic rate of every leaf position was slightly affected by planting density, and the 60,000 plants/hm² was used as density axis of photosynthetic rate of every leaf position.