Based on the data of fog days and the concentrations of SO2, NO2  and PM10 from 2006 to 2012, the characteristics of fogs and air quality and the difference of the influence of sea fog in summer and radiation fog in winter on the air quality in Qingdao are statistically analyzed. The results show that the annual mean number of fog days is 55 days and sea fog days account for 58% of the fog days throughout the year. The highincidence periods of sea fogs are June and July. The annual mean number of pollution days is 30 days and air pollution occurred mostly in winter and spring, and PM10 is the main pollutant in Qingdao. With the process of urbanization, the annual concentration of NO2 tends to increase and SO2 tends to decline. The heavy fogs accompany pollutant days of different levels. The air quality worsens during winter fog days, and the concentrations of SO2, NO2 and PM10 are higher than those in summer.