Based on the meteorological data from 1961to 2008of the middle arid region of Ningxia including Haiyuan county,Yanchi county and Tongxin county,the paper calculated the climate potential productivity of the grasslands in the research area using Miami Model and Thornthwaite Memorial Model.Then the study amended it with soil correction coefficient and further investigated the spatial and temporal variability characteristics of climate-soil potential productivity,so as to explore the limiting factors of grassland productivity and to provide references for local grassland production.The results were as following.Firstly, the climate in the area selected was the warm-dry-type.The average temperature clearly tended to increase, but precipitation tended to decrease with some fluctuation.Secondly,following the climate change trend the climate potential productivity decreased with fluctuation.Compared with temperature,precipitation was the limiting factor that restricted the climate potential productivity.Thirdly,according to the spatial heterogeneity of soil fertility,the grassland climate-soil potential productivity in the three counties was in the following order:Haiyuan county (3 025 kg·hm~(-2)·a~(-1))> Yanchi county (2 993 kg·hm~(-2)·a~(-1))> Tongxin county(2 051kg·hm~(-2)·a~(-1)).