Analysis of meteorological information shows that strong winds and a dust storm were formed at the Hami in the Xinjiang Province and the west part of Inner Mongolia. The storm first moved eastward. As it reached the Inner Mongolia and Hebei Province, it turned southeastward. The structure of the atmospheric boundary layer during the dust storm process is based on data from a 325-meter meteorological tower and radiosonde information. The values of aerosol concentrations during the dust storm are ten times higher than the ordinary days. Instrumental activation analysis was carried on to determine the contents of 30 trace elements in the aerosols. The analytical results show that, besides the great change in content of some chemical elements appearing both in the normal aerosol and in the dust storm aerosols, there exist Eu and Ta only in the latter. The calculation of the enrichment factor shows that relative contents of many elements in the aerosol and in the crust are similar. This was attributed to the dust from soil or rock weathering entering into the air, but the elements Se, Sb, As, and Br mainly came from the burning of coal. Analysis of the meteorological background and the properties of the enrichment factors of some elements in aerosols indicates that the Beijing dust storm aerosol was formed by silt particles brought and mixed into the air by the strong wind. These particles are from the areas where the strong wind formed and passed. It also shows that atmospheric pollutants can travel a very great distance following an air stream.