In order to study the law of soil erosion and water loss in Pinus massoniana forest，proceeding from the main control factor of soil erosion and water loss—rainfall factor, the paper researched the relationship between runoff,sediment yield and rainfall in runoff experimental plots of Pinus massoniana forest under different configuration modes in 2009-2011, it got the following conclusions that①the correlation of runoff and sediment yield with rainfall in each plot was significant, whose optimal regression models were mainly quadratic regression functions, but individual plots were power functions and logarithmic functions, and the coefficient of determination of simulation equation in bare soil plots under the forest was the largest in all the regression models;②in the aspect of runoff characteristics under typical single rainfall events under the same condition of canopy density, the runoff sorting in the plots follows the sequence of pinus massoniana+bare soil> pinus massoniana+bahiasgrass> pinus massoniana+lespedeza, except the plots with canopy density of 0%.With the increase of rainfall, the runoff coefficient of each plot showed an increase trend as a whole, especially in storm and cloudburst;③in terms of sediment yield, the sediment sorting in the plots were basically as follows of Pinus massoniana + bare soil>Pinus massoniana+Lespedeza>Pinus massoniana+Bahiasgrass under each rainfall pattern except the plots with canopy density of 0% and individual plots with canopy density of 24%.