The effects of seeding rate and N fertilizer on leaf area index, dry matter accumulation, grain yield and yield components in oats were studied using split experimental design. The results indicated t㏊t seeding rate and N fertilizer ㏊d significant influence on leaf area index, dry matter accumulation and grain yield. With the increasing seeding and fertilizer rates, leaf area index, aboveground dry matter increased significantly. Oat reached the highest grain yield under 112.5㎏/h㎡ seeding rate, N2 was the best N fertilizer treatment for oat.