Using data from the one per thousand floating population survey in Beijing conducted in 2006, this paper examines structure, distribution, economic status and living arrangement of the floating population in Beijing. Structural changes of the floating population are taking place, with increasing familization of migration. Economic advantages are the major pulling factor in Beijing. Duration of stay in Beijing is quite long for most of the migrants, and many are the de facto Beijingnese. Being informal is characteristic of the ways in which the migrants move to and are being employed in Beijing. The vast majority of the migrant workers are engaged in non-agricultural activities; however, their upward mobility in the city is rare. The paper also discusses difficulties and problems that the migrants face in employment, social security and living conditions.