The meteorological observation data analysis showed that the total solar radiation at Yushu Meteorological Station from 1961 to 2011 presented a decreasing trend in recent 50 years.Analysis of variance showed that the mutation point of total solar radiation at Yushu Meteorological Station appeared in 1978.Before 1978,the total solar radiation was in an increasing trend,then it decreased and presented a decreasing trend after 1978.During years after 1978,the total solar radiation was relatively low,and the annual averge value was reduced by 583.89 MJ/m² compared with that of years before 1978.At the same time,the reduced range of the total solar radiation was different for each month,which was maximum in August and minimum in June.The annual sunshine hours changed in accordance with the total solar radiation.Negative correlations existed between total solar radiation and the annual average temperature,the precipitation of summer and the annual evaporation.Analyzing results show that if the total solar radiation reduces by 100 MJ/(m²·a),then the annual average temperature will rise by 0.03 ℃,the precipitation from May to Septemper will increase by 3.0 mm,and the annual evaporation will increase by 21.0 mm.