Abstract: The study about the effects of ridge and furrow rainfall harvesting system (RFRH) on Elymus sibiricus yield was carried out in Bashang agro-pastoral region during 2009 to 2010 years. The aim was to maintain and increase perennial grassland yields. The soil hydrothermal conditions and roots biomass distribution and yield of E. sibiricus was measured. The results showed that RFRH system could improved soil hydrothermal condition, including increase of soil surface volumetric water content by 9.67%-26.94%, and the soil water storage of 30 cm depth by 13.38%-24.92%, and the soil surface daily minimum temperature, which improved soil surface roots biomass distribution, promoted yields increase by 98%-230%. Treatment of MR60 with 60cm-ridge and 30 cm-furrow had the highest yield 5.34 t/hm2. Compared with the control with the yield of 1.62 and 1.18 t/hm2 of the two year respectively, the average yield of MR60 with 5.34 and 2.79 t/hm2 of the two year increased by 230% and 136%, respectively. RFRH system could significantly increase and maintain E. sibiricus growth and yields under rainfall decreasing and erratic distribution conditions.