为了进一步剖析内江市地区日照时数的长期变化规律，以更好地为农业发展和农业工程设计提供科学依据，基于内江市1971—2011年各月日照时数资料，采用气候倾向估计法，分析内江市41年日照时数的年际变化、季节变化、月变化以及利用滑动t-检验法的突变检验。结果表明：内江市日照时数整体呈现下降趋势，夏季最为明显，其气候倾向率为-36.5 h/10 a，而冬季的气候倾向率只有-7.7 h/10 a；且内江市年日照时数在41年内存在2次突变，其中1980—1982年的突变现象尤为显著，表现为急剧减少的趋势。

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.