Haze is common in cities; its components are mainly sulfur dioxide, nitric oxide and inhalable particle. The hazy condition in Shijiazhuang is very serious, and the air quality is very bad. Two factors contributing to hazy weather in Shijiazhuang are natural and social conditions. The natural factors include U shape geographic position, prevailing wind directions (NNE, N, SSE), perennial wind speed (1.8 m/s), rainless climate, stable atmospheric stratification, dry climate and urban heat land effect. The social factors are as follows: Shijiazhuang is an industrial city and the industrial and mining enterprises in it are unreasonable and dispersed distribution; the main energy structure is coal burning; motor vehicles exhaust; ecological construction cannot keep pace with the speed of urban development. It was pointed out that large polluting enterprises should be moved out of the urban area, middle and small-sized enterprises which consume high energy and serious pollutant should be reduced and banned, low sulphur coal should be spread, scattered coal fired boilers should be dismantled, clean energy should be developed, amount of motor vehicles should be restricted, green area should be enlarged so as to reduce the hazy days.