In view of air quality problems in recent years， the air quality data of Chongqing from December 2013 to December 2017 were analyzed by Ridit and descriptive statistics. The trend of air quality in Chongqing was analyzed. It shows that in the last four years， the air quality in Chongqing has gradually become better. From the monthly variation trend in Chongqing City， the air quality in 12 months for a period of change has gradually become a good trend；from the seasonal change trend，there is seasonal differences in Chongqing Citys air quality， the air quality in summer is the best， followed by the autumn，winter and spring，in winter， the air quality is the worst； from the annual change trend， the air quality in Chongqing has a tendency to be better year by year.