Abstract: Based on "Technical Regulation on Ambient Air Quality Index (on trial)" and the daily air quality index (AQI) from 2015 to 2017 in the central city of Xinyang of Henan province, China, the monthly arithmetic mean values of AQI per year were calculated, by which the temporal changes of air quality of the city were investigated. The results showed that:the air quality of this city in the studied period had been gradually improved year by year and showed markedly seasonal variations, and each summer had better air quality, and each winter had more air pollution days than other seasons that made it a light pollution season, and the air quality in each spring or autumn was oscillated between better and light pollution grade. Meteorological conditions played an important role in air quality changes of this city, especially the weather conditions of cloudy, overcast sky, drizzle, flurry, sleet, the wind from calm to light breeze and with no sustained direction, in particularly north and northerly wind in each winter, and air pollution could be easily taken place. The city's landform was an obstacle to air diffusion. Therefore, it was very important for this city to focus on the influences of weather and season changes as well as the role of urban planning and designing on air pollution control.