Abstract: The design of mixing new additives with loess to promote the efficiency of rainwater catchments materials was put forward. By the rain-simulated experiment, the effect of additive HEC(High Strength and Water Stability Earth Consolidator) and AAM(Active Aluminate Mixture) on the capability, efficiency of mixed loess catchments materials was disscussed. Comparing with the other rainwater catchments materials, the time of runoff yield, and the capability, efficiency of rainwater catchments were studied under the condition of different rainfall intensities, rainfalls and slopes. The results of experiment showed that, comparison by the other materials, the mixed rainwater catchments materials with the additive of HEC and AAM have the rather strong tensile and press strength and the satisfying rainwater catchments efficiency of above 78% but only 1/3 to 1/2 cost of the concrete. This new-type of mixed rainwater catchments materials could be used in the engineering of rainwater catchments in Northwest region for promoting the benefit and reducing the cost of engineering.