The Sanhe small watershed was divided into many slope units with the aid of GIS and its nutrient loss was assessed on the basis of the results of the study slope nutrient loss by means of simulated rainfall, using the universal soil loss equation(USLE).Results showed that the total nutrient(organic matter, TN, TP, TK) loss could be well and truly estimated by calculating sediment in the small watershed, but in estimating of the available nutrients(available nitrogen, available phosphate, available potassium), the nutrients in runoff should not be neglected.In order to accurately estimate the nutrient loss in the small watershed, a runoff distribution model of the watershed should be established and used in combination with the soil erosion model with the aid of GIS.In the Sanhe small watershed, the average quantity of soil loss per year was 5 839t and for the average quantity of nutrient loss per year, the organic matter, TN, TP and TK reached 197.9, 7.42, 3.91, and 174.0 t, respectively.