Abstract: In order to further analyze the change law of sunshine hours in Neijiang City, for better serving for agricultural development and providing a scientific basis for engineering design, based on the sunshine hours date of Neijiang City from 1971 to 2011, the annual, season and monthly variation features of sunshine hours in Neijiang City were analyzed by using annual linear trend analysis，what’s more, the sliding t was used for mutation testing. The results were as follows: on an average in Neijiang City, the annual sunshine duration showed a significant decreasing tendency during recent 41 years; especially in summer with the climate changing rates was -36.5 h/10 a, however in winter, that was 0.77 h/10 a; in addition, there were 2 catastrophes during the time. The catastrophe of the annual sunshine duration around 1981 was remarkable, and it demonstrated an outstanding decrease.