The features of sunshine duration variation in Henan Province and Puyang are analyzed with the linear analysis method by means of the data of 1994 to 2005 from 32 stations. The results indicate that sunshine duration in Henan Province decreased with a tendency of 74.2 hours per ten years, and the decreasing amplitude over the eastern plain areas was obviously greater than those in the western mountainous areas. At Puyang, the sunshine duration decreased by 135 hours per 10 years, with a bigger decreasing amplitude in winter and summer than in spring and autumn. The decrease occured mostly after sunrise and before sunset when the solar altitude angle was relatively low. The meteorological causes include the more and more serious air pollution on an annual basis and the wind velocity decrease, which are favorable for the accumulation of the atmospheric aerosols in the atmosphere at low altitudes and the increase of air humidity and light fog days, resulting in the decrease of atmospheric transparency. The main nonmeteorological factor is that the altitude angle of the obstructions around the observation station is getting higher on an annual basis, which results in the partly sheltering of sunshine. The influence of meteorological factors surpasses that of nonmeteorological factors.