Abstract: Based on 24 years of data （1994-2017） from upical meteorological research stations in various grassland types of Inner Mongolia, the ettect of natm＇al precipitation on the forage yield was analyzed by the comparative and integral regression statistics methods. Natural precipitation significantly affected the tbrage yield in the Inner Mongolia grassland, which exhibited strong seasonal dynamics. The magnitude of precipitation eftects on the forage yield was the greatest from late April to late July. When the natural precipitation amount increased or decreased by 1mm, the tbrage yield was correspondingly increased or decreased by 14, 20, or 12 kg/hm^2 in meadow steppe, typical steppe and desert steppe, respectively. This effect was strongest in the typical steppe. The amount of natural precipitation tended to decline in Inner Mongolia, particularly in the desert steppe. The forage yield decreased with decreasing precipitation, and this response was the most prominent in the typical steppe. These resuhs showed that the forage yield was mediated by natural precipitation in the natural grassland of Inner Mongolia.

Key words: Natural precipitation;Forage yield;Meadow grassland;Typical grassland;Desert grassland