Abstract: ObjectiveTo study the effects of rabdosiae serrae compound preparation on stap hylococcus aureus biofilm.MethodsMinimal inhibitory coh centration(MIC)were tested by doubling dilution,and simulate S.aureus biofilm in vitro be improved Brown plate method.The effects of R.serrae compound preparation in different MICon S.aureus biofilm were determined and confirmed by scanning electronic microscope(SEM).Single layer cells of human floss film were used to test the toxic effects of the compoud preparation.ResultsThe MIC of S.serrae compound to S.aureus was 128 mg/ml, and the MIC reached 192 mg/ml or 256 mg/ml,the viable count of S.aureus on S.aureus biorilm reduced clearly.The tested preparation had no tox ic effects against single layer cells of human floss film.ConclusionR.serrae compound preparation had eliminating effects on the biofilm formed by S.aureus,no toxic effects againsthuman cells in vitro,and a good value to be exploited.The further research of the prescription and the using in clinic was still required.