Abstract: [Objective] The research aimed to evaluate the effects of probiotics on intestinal flora of diarrhea rats induced by antibiotic. [Method] The diarrhea model of rats was build by cefiriaxone. The rats were divided into groups. Except control group, rats in other groups were injected by gavage with ceftriaxone for four clays to build the diarrhea model of rats. Then rats were treated with probiotic preparation for 7 days. The indicators of rats were detected. [ Result ] After they were treated one week, the body weight of young rats rose up. And lactobaeillus and bifidobacterium recovered to control level, but they were still better than natural recovery group. [Conclusion] The probiotics could improve antibiotic-induced diarrhea in rats and have certain role for flora imbalance.