Abstract: To study the regulation effect of Shengmai San(SMS)on intestinal dysbacteriosis, ceftriaxone sodium was used to induce intestinal dysbacteriosis in vitro, together with bacteria cultured in the selective medium and enumerated by plate counting, and the short chain fatty acid were also analyzed. The results showed that SMS(16. 5, 11. 2, 5. 5 mg/mL)could significantly inhibit the proliferation of such potentially harmful bacteria as Enterococci and Enterobacteriaceae, while promoting the proliferation of Lactobacillus and Clostridum. Compared with the model group, the proliferation of Enterococci and Enterobacteriaceae was inhibited by 24. 9% and 19. 1%, while the proliferation of Lactobacillus and Clostridum was increased by 22. 3% and 25. 8%, respectively, in the medium dose of SMS group(11. 2 mg/mL)at 24 h. Meanwhile, SMS in different concentrations significantly increased the accumulation of acetic acid and propionic acid generated by gut microbes which could significantly inhibit the proliferation of harmful bacteria. SMS showed probiotic effects on intestinal microflora imbalance induced by antibiotics in vitro.