Objective To study the effect of cefazedone sodium on mice infected by clinically isolated bacteria.Methods The mice were injected clinically isolated strains of staphylococcus aureus,pseudomonas aeruginosa(P.aeruginosa)and escherichia coli by intraperitoneal route.Then the infected mice were injected cefazedone sodium by subcutaneous route.Results Cefazedone sodium of 10 mg/kg,20 mg/kg and 40 mg/kg decreased the mortality rate of mice infected by staphylococcus intermediu R1725,staphylococcus aureus 1743,pseudomonas aeruginosa R1620,pseudomonas aeruginosa R1598,escherichia coli R1598,escherichia coli W1867 and enterococci W1999.Conclusion Cefazedone sodium can protect mice infected by clinically isolated staphylococcus aureus,pseudomonas aeruginosa,and escherichia coli.