Objective To study the changes of vaginal lactobacilli in often washing vagina women for preventing and curing vaginitis.Methods Adopt vaginal fluid smear,Gram's stain examination the half value of vaginal lactobacilli in 483 cases(observation group)who often washing vagina and in 557 cases(control group)who does not often washing vagina.Results In observation group,the detectable rate of vaginal lactobacilli is 14.11% who wash vagina once,average 3 days,the detectable rate of vaginal lactobacilli is 25% who wash vagina once average 3 to 10 days,the detectable rate of vaginal lactobacilli is 84.92% in control group.Compared two groups,it has the distinctive difference(P=0.0006).In observation group the detectable value of vaginal lactobacilli is 16.56% who wash vagina once average 3 days,the detectable value of vaginal lactobacilli is 53.13% who wash vagina once average 3 to 10 days,the detectabl value of vaginal lactobacilli is 192.28% in control group.Compared two groups,it has the distinctive difference(P=0.0004).Conclusion Vaginal lactobacilli obviously decrease in often washing vagina women to prevent and cure vaginitis and it can not keep normal vaginal microorganism environment.