Objective To study the effects of traditional Chinese medicine Zuojin Pill on gastrointestinal system.Methods Through ig giving 0.1％ methyl orange solution,the gastric residual rate was calculated,and the effect of Zuojin Pill on gastric emptying in mice was observed.By ig administration of 5％ carbon powder,the advance rate of carbon powder was calculated,and the effect of Zuojin Pill on intestinal motility in normal mice and the antagonistic effect on intestinal motility hyperfunction induced by neostigmine were observed.Effect of Zuojin Pill on contraction of isolated guinea pig ileum induced by histamine was observed.After D-xylose solution was ig given to rats,the serum xylose level was determined 1 h later,and the effect of Zuojin Pill on rat intestinal absorption was observed.The anti-diarrhea effect of Zuojin Pill was observed by giving castor oil to mice.At the same time,we have made a comparison between Zuojin Pill and Wuji Pill-berberine,to evaluate the rationalization of Zuojin Pill.Results It was obvious in experimental results that Zuojin Pill had a regulating effect on gastrointestinal system.Zuojin Pill dose-dependently inhibited the gastric emptying.Zuojin Pill demonstrated more effective suppression on the accelerated movement induced by neostigmine,but did not inhibit normal intestinal transit in mice.Zuojin Pill markedly inhibited sperm motility in mice.Zuojin Pill concentration-dependently inhibited the contraction intensity of isolated ileum muscles in guinea pigs induced by histamine.Zuojin Pill markedly inhibited diarrhea induced by castor oil.Compared with Wuji Pill-berberine,the effect of Zuojin Pill on gastrointestinal system was more visible in the same dose.Conclusion Zuojin Pill has obvious regulation effect on the gastrointestinal tract,there are indications that the application of Zuojin Pill to clinic is scientific and reasonable.