Through setting four density of 37500, 48000, 58500 and 69000 plants/hm2 in feeding maize shaandan 8806, it is founded that the feasible planting density of shaandan 8806 is 63000 plants/hm2. The reasonable leaf area index is about 5.6 during spin stage. Under the density, the Net assimilation rate can reached 14.3 g/(d.m2) during jointing to mature.