Through the simulated rainfall experiment, the effects of slope and antecedent soil water content on the process of rainfall runoff and sediment on bare land and alfalfa land of coarse texture soil were investigated. The experiment treatment included three slopes（5°, 15° and 25°）and three antecedent soil water content（low, middle and high）. The results showed that the processes of runoff on bare land and alfalfa land were at first increased and then leveled-off under different slopes and antecedent soil water content, and the effects of slopes on runoff volume were marginal. Sediment losses were greatly increased with the increasing slopes, which were increased firstly and then tended to be stable, and also greater changes occurred in bare land. Both of the runoff volume and the mean infiltration were significantly affected by antecedent soil water content. Under the same slope gradient, when antecedent soil water content increased from low to middle, and from low to high, the runoff volume of bare land increased 38.2%—52.8%, and 39.7%—42.8%, respectively, while the runoff volume of alfalfa land increased 27.3%—77.8% and 45.5%—91.1%, respectively. Slopes had significant influences on sediment losses and sediment concentration. Under the same antecedent soil water content, when slope increased from 5° to 15°, and from 15° to 25°, the sediment losses of bare land increased 96.3%—268.7%, and 6.9%—40.3%, respectively, whereas the corresponding values of alfalfa land increased 81.1%—384.2%, and 61.7%—169.9%, respectively. The results showed runoff volume and sediment losses of alfalfa land were significantly lower than bare land at same slope and antecedent soil water content. The findings indicate that antecedent soil water content and slope of coarse texture soil play important roles on the process and amount of soil erosion. The vegetation not only reduces runoff by canopy interception, but also decreases antecedent soil water content through consuming soil moisture.