OBJECTIVE:To explore the risk factors of adverse reaction of cefazolin drugs by Logistic model. METHODS:Re-lated information was collected from the information system of our hospital,and SPSS 19.0 software was conducted for statistical analysis. RESULTS:Totally 855 patients were enrolled,30 of which had adverse reactions(3.51%). According to the results of Logistic analysis,intravenous administration with the concentration of ≥20 mg/ml (OR=7.857,95% CI:1.566-39.431,P=0.003) was the risk factor of adverse reaction of cefazolin drugs when single dose was above 2 g (OR=13.75,95% CI:2.423-78.028,P<0.001)at 0:00-8:00(OR=2.340,95% CI:1.043-5.253,P=0.034). CONCLUSIONS:Adverse reaction of ce-fazolin drugs might be dose-related type. The drug adverse reaction predictive thresholds are single dose above >1.75 g with ad-ministration time of 0:00-9:05 and concentration of above 7 mg/ml. According to the predictive thresholds,the risk of patients with adverse reaction can be predicted to promote safe and effective use of cefazolin.