Jidan 88, a popular high starch corn variety current in use was used as material in the experiment,and five density were designated, i.e., 30 000, 45 000, 60 000, 75 000 and 90 000 plants/hm². Repeat 3 times. Yieldof the first to fifth marginal row was determined. Changes of corn grain energy（starch, fat, protein） of the first to fifthmarginal row under different densities was studied in order to make clear effects of the density, marginal changes oncorn grain energy quality.