Abstract: The effect of swine manure application on nitrate nitrogen leaching was investigated in the Yellow River irrigation area of Ningxia. The field experiment was conducted with 3 Treatments: Traditional fertilization 225 kg N kg·hm^-2 without swine manure (CK), traditional fertilization with swine manure 4500 kg·hm^-2(T₁) and traditional fertilization with swine manure 9000 kg·hm^-2 (T₂). Nitrate nitrogen leaching rates were measured for 30, 60, 90 cm depth soil layers with a resin core absorption method. The results indicated that the nitrate leaching losses of T₁ and T₂ treatments ranged from 9.33 to 14.04 kg·hm^-2(pure nitrogen), which accounted for 4.2%-6.2% of applied nitrogen fertilizer. Compared to CK, the nitrate leaching losses of T₁ and T₂ increased by 2.6% and 2.1% at 30 cm depth, increased by 1.5% and decreased by 1.3% at 60 cm depth, decreased by 8.7% and increased by 4.0% at 90 cm depth, respectively. The difference did not reach statistical significance among CK and T₁ and T₂ in nitrate leaching loss at 30, 60 and 90 cm depths. However, there was a declining trend of nitrate leaching at deep soil layers of treatments. The key period of nitrate leaching loss was from spring reviving to early filling stage, which had a higher daily leaching loss than the average of the whole growth period, and accounted for 58.7%-75.3% of total leaching loss. Compared with CK, the yields of T₁ and T₂ increased by 9.3% and 12.5%, respectively.