Atmosphere bioaerosols was always closely linked with the health of human beings and flora and fauna, however, recent studies suggested that the bio-aerosols may impact the environment and climate change directly by acting as cloud condensation nuclei (CCN) and/or ice nucleation (IN). Unfortunately, there was still little knowledge about the composition of microbial community of the biological ice nucleis in the precipitation, especially, in China mainland. At present study, the precipitation samplers were taken from the Beijing city area. The sampling was carried out in different months in 2011 and 2012. The bacterial diversity was analyzed using the 16S rRNA gene sequencing based approaches. Seven clone libraries were established resulting from the different rain-water sampling months. The results indicated that Proteobacteria (75.6%~100%) were dominant in the precipitation including Alphaproteobacteria, Betaproteobacteria,and Gammaproteobacteria. While other bacterial communities such as Bacteroidetes, Actinobacteria, Deinococcus-Thermus, Cyanobacteria, Nitrospira and Firmicutes were involved as well. Furthermore, a small proportion of undetermined bacteria(TM7, 1.2%~7.2%) were also found. In addition, microbial diversity in the snow water samplers was obviously much more than that in the rain-water samplers, which suggested that some biological ice nuclei may present and influence in the formation of precipitation. Moreover, results showed that Pseudomonas, in which some strains with high effective ice nucleation activity, was also found in the samplers. Therefore, further concerns should be done for the climatic effect of these microbes.