Abstract: Objective: To study the immunization effects of M tuberculosisMPT64 DNA vaccine Methods: The plasmid DNA was purified by Qiagen plasmid purification kit 25 BALB/c were randomized into 4 groups DNA vaccination was done by injection of 50μg of plasmid DNA in 50μl saline into the quadriceps muscle of each hind leg on three occasions at 3 week intervals Control mice received saline or empty plasmid only or a single subcutaneous injection of BCG MPT64 specific antibodies were determined by ELISA Results: Purified plasmid DNA did not contaminate with RNA, its OD260/OD280was higher than 18, 2mg of plasmid DNA per 2000ml culture could be obtained The mean absorbrance plus two standard deviations of the mean for normal mouse serum was adopted as the cutoff absorbance MPT64 specific antibodies increased in 4 mice immunized with JW4303 MPT64 recombinant plasmid Increasing titers of specific IgG were generated over the course of immunization Conclusion: M tuberculosis MPT64 DNA vaccine, which was immunized mice by muscle infection, could inducespecific humoral immune response of some mice, there was difference of immunization effect among the mice