Abstract: Changes in plant species diversity and productivity along gradients of precipitation and elevation were studied in the Xilin River Basin, Inner Mongolia using a transect approach. Species richness ,diversity, productivity were negatively correlated with mean annual temperature, ≥10℃ cumulative temperature, and aridity. Inverse relationships were also found between species richness ,diversity, productivity and precipitation, elevation, soil organic carbon and total nitrogen content. The species richness ,Shannon-Wiener diversity index, and productivity of the communities declined with a decreasing elevation, precipitation, soil organic carbon and total nitrogen content, and with increasing mean annual temperature and aridity. The effects of the land use type and intensity were also very strong.