Abstract: By using alkali soluble and acid sinking method, total flavonoids of Sambucus chinensis Lindl were extracted, and its antibacterial effect were studied in this paper. The extraction conditions including solid-liquid ratio, extraction temperature, extraction time, p H of xetraction liquid of flavonoids from Sambucus chinensis Lindl were optimized by single factor experiments and orthogonal experiments, and meanwhile the sinking efficiency of total flavonoids were studied by acidic p H precipitation, and the antibacterial activity of total flavonoids was studied by filter paper discs method and turbidimetric method. The results showed that the optimum extraction conditions of total flavonoids of Sambucus chinensis Lindl were as follow: solid-liquid ratio1∶ 40 ( g/m L) , extraction temperature 80 ℃, extraction time 45 min, extraction liquid p H10, in which the extraction rate of total flavonoids of Sambucus chinensis Lindl was 3.11%.Adapting the extract to p H3.5 with HCl could better precipitate about 2.15%total flavonoids of Sambucus chinensis Lindl.Total flavonoids of Sambucus chinensis Lindl had a stronger antibacterial activity on Staphylococcus aureus, Bacillus subtilis, Escherichia coli at acidic p H4 ~5 than at neutral p H and alkaline p H value, and these bacteria conductivity was increased by total flavonoids. The minimum inhibitory concentration of total flavonoids of Sambucus chinensis Lindl on three bacteria were 0.63, 1.25, 2.50 mg/m L, respectively. The extracting process of total flavonoids from Sambucus chinensis Lindl by using alkali soluble and acid sinking method was simple and inexpensive, and its total flavonoids had a great antibacterial activity, in which played a foundation on the development and utilization of total flavonoids of Sambucus chinensis Lindl.