Objective To observe the possible mechanism of Dahuang Mudanpi Decoction（ 大黄牡丹皮汤） in treatment of intestinal disease. Methods Five groups including bacillus group

high dasage group

middle dasage group

low dasage group and cephalosporin group. The bacillus group was made of suspension of 108 cfu/ml lactobacillus bulgaricus. The high dasage group

middle dasage group and low dasage group separately added freeze-dried powder of Dahuang Mudanpi Decoction with 4 g（ 40 mg/ml）

1 g（ 10 mg/ml）

and 0. 25 g（ 2. 5 mg/ml） on the basis of bacillus group. The cephalosporin group was added 1 g（ 10 mg/ml） ceftriaxone sodium powder on the basis of bacillus group. All of these groups were put into microorganism incubator with 37℃

5% CO2 for 24 hours. The concentration of bacterium of each group was detected at the 0

2 nd

4 th

6 th

8 th

10 th

12 th

14 th

16 th

18 th

20 th

22 th

24 th hour. The concentration of lactic acid L and lactic acid D was detected at the 0

2 nd

6 th

10 th

14 th

18 th

22 th hour. Results The concentration of bacterium

lactic acid L and lactic acid D of each group at each time point was significant different（ P < 0. 05）. Simultaneously compared with bacillus group and low dasage group

the concentration of bacterium in other groups at each tome point was significantly different（ P < 0. 05）. Simultaneously compared with cephalosporin group

the concentration of bacterium in high dasage group

middle dasage group and low dasage group were increased at each time point（ P < 0. 05）. Simultaneously compared with high dasage group

the concentration of lactic acid L and lactic acid D of each group at each time point was significant different（ P < 0. 05）. Compared with cephalosporin group

the concentration of lactic acid L and lactic acid D of each group at each time point was significant different（ P < 0. 05）. Conclusion Dahuang Mudanpi Decoction can improve the reproduction ability of lactobacillus bulgaricus and significantly increase the output of lactic acid L and lactic acid D

the high dosage gorup being especially remarkable.