Abstract: Effects of density and nitrogen and phosphate fertilizers on yield and economic benefit of corn ground covered by plastic film and the interrelations of the three factors were studied by revolving regression designed field experiment.Based on the experimental data a regressive yield and economic model were established.Then based on analysis of the model suitable rate of dressing of the two fertilizer at current condition can be determined.It was also concluded that for increasing the corn yield and economic benefit nitrogenous fertilizer is more important than density,and density is more important than phosphate fertilizer.