Neural network black box model for predicting the slope runoff and sediment yield and two empirical equations for calculating the slope runoff and sediment yield were established with the basis of practical field data of slope runoff and sediment amount by artificial simulated rainfall experiments. In additional, particle swarm optimization algorithm is used to inquire the empirical equation’s unknown parameters based on least square method. And results show that, neural network model might represent the nonlinear relationship between runoff, sediment amount and each impact factor excellently. Furthermore, predicted results are satisfactory and its relative error mean is around 10%. Empirical equations are reasonably and reliable, its relative error mean is less than 20%. These two methods provide an operable means for such intricate research of slope runoff and sediment yield predication and calculation.