Abstract: In order to make better use of the climate resources in Nanchong city, forecast the future climate change trend in Nanchong city, and promote the production and life in the region. Based on the ground meteorological observation data of Nanchong city from 1970—2019, three climate elements: temperature, precipitation and sunshine, were selected. By using the linear regression method and R/S analysis method, the characteristics of inter-annual and four-season climate change in Nanchong city over the past 50 years were analyzed, and the future inter-annual and four-season climate change trends in Nanchong city were predicted. The results showed that, from 1970—2019, the annual average temperature and the four-season average temperature showed an overall upward trend; the annual, summer and autumn sunshine hours showed an downward trend, and the spring and winter sunshine hours showed an upward trend; precipitation showed an downward trend in autumn, and the rest showed an upward trend. In the future, the annual average temperature and four-season average temperature in Nanchong city will show a downward trend; the sunshine hours in Nanchong city for the annual, spring, autumn and winter will show a downward trend, and the sunshine hours in summer will show an upward trend; the annual, spring, autumn and winter precipitation will show a downward trend, and the summer precipitation will show a upward trend.