Liaoshu No. 6 was used as material to investigate the effects of topdressing rate of N(N₁ :0 kg/ha;N₂ :60 kg/ha;N₃:105 kg/ha;N₄ :180 kg/ha;N₅ :225 kg/ha)on dry matter accumulation characteristics and yield of potato based on 750 kg/ha NPK (15∶15∶15) compound fertilizer as the base fertilizer through film mulched drip irrigation.The results showed that the dry matter accumulation and distribution ratio of potato leaf and stem increased with the increase of nitrogen application rate,and N₅ treatment had the highest values;the dry matter accumulation and distribution ratio of potato tuber increased first and then decreased with the increase of nitrogen application rate,and N₃ treatment had the highest values.The translocation amount and ratio of dry matter,average tuber weight,tuber weight per plant and yield of N₃ treatment were the highest.The yield of N₃ treatment was 46.5 t/ha,which increased by 92.9%,78.2%,9.7%,18.6% compared with N₁,N₂,N₄,N₅ treatments.Correlation analysis showed that there were significantly positive relationships between dry matter accumulation,dry matter accumulation rate,dry matter translocation amount,dry matter translocation rate and average tuber weight,tuber weight per plant,yield.The above results indicated that the optimum N topdressing rate was 105 kg/ha.