Abstract: In order to solve the problem of absenting rationality and system on design method of level ditch of runoff harvesting,based on theory analysis,the systematic design methods and calculated formula were put forward.The distances between ditches were decided by the water requirement of local vegetation combining with the designed potential rainfall amounts.The equivalent width and depth were estimated by the maximum potential rainfall amount during a storm even of the locality,the highest rainfall intensity and the soil infiltration rate and etc.factors.The feasibility of the method of level ditch of runoff harvesting was demonstrated by the practical engineering application.Compared with traditional design methods,this method was more rational and(reliable,) could be applied wildly.