Objective: To study the antibacterial activity of the flavonoids from Trollius ledebouri Reichb (FTLR) were observed in vivo and in vitro. Method: By methods of tube continuous dilution and agar plate diffusions to 14 strains of bacteria

for example Staphylococcus aureus

minimal bacteriostatic concentration (MIC) and minimal bactericidal concentration (MBC) of FTLR were determined in vitro. To evaluate antibacterial activity of FTLR in vivo

the model of mice infected by the type strain of S. aureus 26002-6 was preparated and they were randomly divided into groups of 440

220

110 mg·kg-1 of FTLR

2 400 mg·kg-1 Jinlianhua tablet (2 400 mg·kg-1 of Jinlianhua tablet and 440 mg·kg-1 of FTLR were the same of crude drug dose)and model control group and the mortality of mice in different groups was calculate in 24

48 h mice after infection. Result: In bacteriostasis experiment in vitro

FTLR shows obvious bacteriostatic activity on the used strains and its MIC and MBC were lower than those of Shuanghuanglian oral liquid. In bacterostasis activity in vivo

the mortality of mice in all groups of FTLR was lower than in modle control group in 24

48 h mice after infection. Conclusion: FTLR has obvious inhibition effect on several kinds of bacteria in vitro and protective effect on infected mice induced by S.aureu 26002-6.