To rationally use native species in the loess hilly-gully region and find appropriate mixture ratio of native species for artificial grassland construction, Bothriochloa ischaemum and Lespedeza davurica were sowed by the seven row ratios of 0:10, 2:8, 4:6, 5:5, 6:4, 8:2 and 10:0 in a terraced field. The seasonal soil moisture characteristics, yearly aboveground biomass and water use efficiency were investigated and compared in two years with different rainfall amounts(663.4 mm in 2011 and 458.2 mm in 2012). Results indicated that soil water consumption and replenishment were closely related with the mixture ratio of the two species in the mixture grassland, mainly affected by yearly rainfall amount and seasonal distribution. In 2011, soil water supplement reached the 20-260 cm soil layer, and the spatial and temporal difference of soil moisture between mixture ratios and soil layers were reduced because of plentiful rainfall in the rainy season. Both in 2011 and 2012, Bothriochloa ischaemum and Lespedeza davurica mixtures at 6:4 and 8:2 ratios had higher aboveground biomass production and water use efficiency.