A field simulated rainfall experiment was designed to quantify effects of mulch cover on hillslope soil erosion and nutrient loss in the black soil region of the Northeast China.The experiment treatments included one fertilizer input(150 N and 75 P kg/hm²) and three mulch cover levels(bare land,2 and 4 kg/m² corn mulch cover).Simulated rainfalls were applied at a rate of 90 mm/h for 60 minutes on slopes of 5°.The plot size was 10 m long and 1 m wide.The results show that when corn mulch cover was 2 kg/m²,runoff decreased by 87% and the soil loss reduced by 99.86%,respectively,comparing to the bare land.For 4 kg/m² of corn mulch cover,no runoff occurred.Under the 2 kg/m² mulch cover treatment,NO^-₃—N and pO^3-₄—P concentrations in runoff were 5.52 and 4.25 times higher than them from the bare land,but the total losses of NO^-₃—N and pO^3-₄—P in runoff were similar.NO^-₃—N and pO^3-₄—P in eroded sediment from the lowly covered plot were 4.38 and 2.93 times respectively greater than them from the bare land;but the total losses of NO^-₃—N and pO^3-₄—P in eroded sediment from mulch cover treatment reduced by 99.3% and 99.6%,respectively.Therefore,the proper corn mulch cover is important for protecting soil quality and reducing agricultural non-point pollution.