We conducted a field study to examine the relationships between the root-shoot ratio dynamics and precipitation and temperature for the typical Leymus chinensis steppe recovering from grazing in Inner Mongolia. A former pasture land that had been fenced off for two years was selected for the study; and aboveground and belowground biomass were collected from the study site along with local precipitation and temperature observations during the study period to be used in the analysis. Our results indicated that: (1) The seasonal change of both aboveground and belowground biomass in Leymus chinensis demonstrated a pattern with a single peak occurring in August. (2) the root-shoot ratio showed seasonal variation, with relatively high values at the beginning of and the end of the growing season. The minimum ratio occurred in late August when the aboveground biomass reached its maximum. (3) the monthly root-shoot ratio was significantly correlated (p<005) with the monthly precipitation two months previous, and with the monthly mean temperature of the previous month. A regression model was built with the root-shoot ratio as the dependent variable and precipitation and temperature as independent variables. This regression could be used to model the monthly root-shoot ratio dynamics of Leymus chinensis steppe during the growing season. Therefore, precipitation and temperature information from current and previous months can be used to make predictions for the next month. These predictions could be used to plan vegetation management and provide more accurate estimates for steppe ecosystem productivity and carbon stock dynamics.