Abstract: Antibacterial effect of extraction from Hibiscus mutabilis leaf on E.coli O₁ and Staphylococcus aureus 91053 were studied, respectively.With the double broth dilution methods and spread plate methods, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the extract on E.coli O₁ and Staphylococcus aureus 91053 were determined to draw antibacterial curves.The results showed that MIC and MBC of the extraction for E.coli O₁ were both 0.25 g/mL, 8, 4, 2 and 1 times MIC could completely kill the test strain at 6, 14, 18 h, respectively;MIC and MBC of the extract on Staphylococcus aureus were both 0.5g/mL, 4, 2 and 1 times MIC of the extraction had better effect and could thoroughly kill the test strain at 8, 12 and 16h, respectively.The extraction could be bactericidal to the two test samples efficiently.