Eight maize varieties in the market of Jilin Province were selected and they were grown at five planting density to study effect of planting density on the commodity quality,i.e.,30000,45000,60000,75000,and 90000 plants per hectare.The results showed that with the increase of planting density bulk density changed differently according to varieties.Bulk density of maize seed at 30000 plants/ha decreased compared with higher density.Grain volume decreased as the planting density increased,but the changes varied with different varieties.The grain plumpness reduced as the planting density increased,such as ’Jidan 79’.Also,the changes varied with different varieties.Grain plumpness of few varieties tends to increased as the planting density increased,such as ’Jidan 27’.