In this paper, the meteorological conditions for low-level pollution in the district situated in the northern suburbs of Nanjing, China, a base of chemical industry, are analyzed. Some major conclusions are reached as follows:1. The frequency of inversion in the district is the highest in autumn and winter. The thickness and intensity of inversion are at their maximun in winter.2. The atmospheric stability tends to become neutrally stratified as altitude increases. However, stable stratification is still observed at higher levels in winter. The frequency of stable stratification can reach as high a value as 47% during the day in winter, especially at heights of 200-300m. Obviously, this has much to do with the frequency inversion.3. The mixing depth is the smallest in winter and after midnight till early morning in day. It is only about 444m.