Objective To analyze the polymorphisms of 20 microsatellites in 11 strains of mice by PCR and to explore a new method for inbred strain mice genetic monitoring.Methods 20 short tandem repeat(STR) primers were used to amplify DNA in 11 inbred strains of mice(C3H,DBA,BALB/c,C57BL/6,C57BL/6-Bg,C57BL/10,TA1,TA2,T739,M615 and SCID).The polymorphisms information of C57BL/6-Bg,C57BL/10,TA1,TA2,T739,M615 and SCID were acquired according to those of C3H,DBA,BALB/c and C57BL/6.Results 193 out of the 220 amplified bands were in anticipation.Conclusion The results showed that different stains of mice could be differentiated by use of polymorphisms of the 20 microsatellites.It revealed that genetic diversity is abundant in inbred mice.These results have instructive significance for mice genetic monitoring.