According to the hourly meteorological data and hourly air pollutant data in Anshan City,Lia-oning Province in 2019,a response relationship model was established based on the generalized additivemodel ( GAM) considering confounding factors such as the background value of urban air pollution andmonths. The concept of relative risk ( RR) was introduced to calculate the quantitative relationship. Theinfluence of three meteorological factors ( wind speed,temperature,relative humidity) on PM2.5 and SO2was analyzed. The results show that all the meteorological factors have threshold effects on PM2.5. Theinfluence percentage of wind speed is the highest. When the wind speed changes below 4 m/s,the rela-tive change of PM2.5 concentration per unit increment is -7.63%. The concentration of PM2.5 changes ina U-shape with the increase of temperature. The threshold of temperature is 10 ℃,and the relativechanges of PM2.5 concentration caused by the temperature are -0.56% below 10 ℃ and 0.6% higherthan 10 ℃. When the relative humidity is between 18% and 85%,the increase of relative humidity of-ten leads to the increase of urban PM2.5concentration. When the response variable is SO2,the relativechanges of SO2 concentration corresponding to per unit reduction of wind speed,temperature andrelative humidity are -0.91%,-0.43% and 0.98%,respectively.