Abstract: Objective To analysis the carrying status in common bacteria identified from the upper respiratory tract of SPF mice. Method The bacteria were isolated and cultured, stained, examined under microscope, biochemical reaction, and identified by Vitek 2 compact automatic bacterial identification. Result There were 8 species of common bacteria in the respiratory tract of SPF mice, which were divided into 4 classes according to carrying rate: the first category was 98. 6% carrying rate of Granulicatella adiacens; the second category were 45% - 65% carrying rate of Staphylococcus sciuri and Sta.xylosus; The third category were Enterobacter cloacae, Escherichia coli, Proteus singularis, which carrying rate were 25% -45%; the fourth category were less than 10% carrying rate of Acinetobacter, Klebsiella pneumoniae. Conclusion The species and carrying rate of common bacteria from the upper respiratory tract from SPF mice were obtained by Vitek 2 compact. This result would provide support for the evaluation of the microbial quality of SPF mice and the selection of SPF mice for scientific research projects.