Abstract: In order to study the effects of Paspalum notatum Flugge and its ground cover on water conservation,the experiment was carried out by Lysimeter and the depth of surface runoff and subsurface flow was gained for different treatments.The results indicated that,runoff components have obvious differences because of different treatments.The total depth of runoff in treatment A(coverage of Paspalum notatum Flugge),B(mulching of Paspalum notatum Flugge),C(bare slopeland) was 1 245.24,1 453.81 and 1 383.23 mm respectively,of which the depth of surface runoff was 24.46,50.2 and 592.07 mm respectively,while the depth of subsurface flow was 1 220.78,1 403.61 and 791.16 mm respectively.The empirical equations in treatment A,B,C are parabola,the relative coefficient of which is 0.933,0.861 and 0.810 respectively between the depth of surface runoff and precipitation.The analysis results showed that the differences of the depth of surface runoff are very significant between different treatments.