With Chlorophyll Meter SPAD-502 and Canopy Analyzer AccuPAR LP-80, the spectra characteristic effect of different density-resistant maize variety on planting density was studied, and the effect of planting density on photosynthetic performance of maize was discussed. The materials of the experiment were Yinong-103, Xianyu-335, Zhengdan-958 and Denghai-661, the row spacing was 80 cm×40 cm, the plant spacing was gradually changed from 1m to smaller spacing, the densities were 3.33, 3.70, 4.17, 4.50, 4.76, 5.56, 6.67, 6.80, 8.33, 9.00, 11.11, 11.20 and 16.67 planting·m-2 respectively. We studied spectra characteristic effect on planting density, and investigated maize photosynthetic characteristics and density-yield relationship to get high yield. This research can be good case of using maize spectra characteristic to reflect plant photosynthetic characteristics and canopy architecture. The end of this paper was to explore density effect on yield with spectroscopy means.