Abstract: The temporal and spatial variation of annual,seasonal,and monthly sunshine duration in Xingjiang Uygur Autonomous Region and its cause was analyzed by using the methods of climate trend rate, abrupt detection and correlation analysis, based on the sunshine duration, radiation, rainfall, cloudiness, vapor pressure and wind speed data from 42 meteorological stations in Xingjiang Uygur Autonomous Region from 1961 to 2010. The results showed that the spatial distribution of annual, seasonal and monthly sunshine duration reduced from east to west in Xingjiang. The top value occurred in summer, and followed by spring, autumn, and winter. The annual and seasonal solar radiation in Xingjiang declined in last 50 years, especially in winter. The regional average annual sunshine duration declined at the rate of 23.4d/10y. The annual sunshine duration was extremely deficient in 1992 and 1993, and extremely excessive in 1967. Meanwhile nearly half of the stations in Xingjiang had obviously abrupt in the middle of the 1980s. The sunshine duration increased slightly in spring, but obviously declined in summer, autumn, and winter at the rate of 4.5-13.3h/10y, especially in winter. Sunshine duration showed obviously spatial variation from long term perspective. The annual and seasonal sunshine duration declined in north of 38°N（P＜0.05），and obviously increased in south of 38°N(P＜0.05).The sunshine duration reducing might be associated to humidity increasing and wind speed reducing in north of 38°N in Xinjiang.

Key words: Sunshine duration, Solar radiation, Climate trend rate