Abstract: The air pollution caused by atmospheric particulates in Beijing city is one of the problems to be solved. In order to analyze the pollution level of atmospheric particulates in Beijing city and the influence factors, with the research on PM10 and PM2.5, the authors sampled at nine areas in Beijing city during winter in 2005. The results are concluded as follows. The pollution level in Beijing is very serious. Because of the influence of pollution sources at each sampling area, the pollution level of PM10 and PM2.5 in different regions reduces from main traffic road region to industrial region, decreases from rural region to commercial region to residential region, and not all the spatial distribution regulations of the concentrations of PM2.5 are the same as PM10. As weather conditions keep stable, the hourly variation of PM10 and PM2.5 concentrations presents regularly, the temporal variation mostly depends on the variety of contaminations released to the environment. Meteorological conditions are the important influence factors of PM10 and PM2.5 pollution level. A correlation analysis indicates significant negative correlation between the concentrations of atmospheric particulates and the temperature. And the same situation is also observed between the particle concentrations and wind speed. Positive correlation is found between relative humidity and the concentrations of atmospheric particulates. As the temperature inversion layer forms and becomes stronger, the concentrations of atmospheric particulates increase as well.

Key words: PM10 and PM2.5, pollution level, influence factors, winter, Beijing city