Abstract: OBJECTIVE To research the antimicrobial effect in vitro of Rhizoma Coptidis, furazolidone and the two drugs in combination on Escherichia coli, Bacillus pyocyaneus, Staphylococcus epidermidis, and Shigella dysemeria. METHODS The minimal inhibitory concentration (MIC) of Rhizoma Coptidis, furazolidone and the two drugs in combination on the 4 strains of pathogenic bacteria were determined respectively by the method of tube double dilution method combined with agar plate method. RESULTS The antimicrobial effect was enhanced when Rhizoma Coptidis combined with furazolidone. CONCLUSION The results indicate that the combination of Rhizoma Coptidis and furazolidone have synergistic effect.