Objective To observe the treatment of bacterial vaginosis in pregnant women. Methods 107 cases of bacterial vaginosis in pregnancy were allocated into two groups at random. One group use Living Preparation of Lactobacillus and the other use Metronidazole. Results cure rate of living Preparation of Lactobacillus was 85.1%. Compared with Metronidazole,the difference was insignificant. Conclusions Lactobacillus is a safe and effective therapy to bacterial vaginosis in pregnant women without side effect.