The data of air pollutants(PM_2.5, PM₁₀, NO₂, SO₂ and O₃), meteorological data(daily mean temperature, daily mean relative humidity) and daily outpatient visits of respiratory system in a grade A hospital of Yancheng City during 2014—2018 were collected. A time series semiparametric generalized additive model was used to analyze the relationship between shortterm exposure to air pollutants and respiratory hospitalization, and the maximum effect value of lag days was adopted to evaluate the excessive risk of the effect of air pollution on daily outpatient visits of respiratory system．According to the research results，the annual average concentrations of PM_2.5, PM₁₀, NO₂, SO₂and O₃ were 48.4 , 81.8 , 26.3 , 15.8 and 111.2 mg/m³, respectively．PM₁₀ and PM_2.5 concentrations were higher than national class II standard．With an increase of 10 mg/m³ of PM_2.5, PM₁₀, NO₂, SO₂and O₃, the increase of daily outpatient rate of respiratory system would be 0.52 %, 0.31 %, 3.54 %, 4.36 %, and 0.03 %, respectively, and SO₂ showed strongest effect. The shortterm exposure of air pollutants affects the daily outpatient rate of respiratory system, and there are lag effects, of which PM_2.5, PM₁₀. NO₂ and SO₂ have stronger effects.