Objective:To evaluate the bacteriostatic efficacy of chloramphenicol eyes drops available on market.Methods:According to the 1121 bacteriostatic efficacy test method in Chinese Pharmacopoeia(2020 edition)volume IV general requirements,test strains including Staphyococcus aureus,Pseudomonas aeruginosa,Candia albicans and Aspergillus niger were selected to assess chloramphenicol eye drops from eight different companies.Results:The test results showed that chloramphenicol eye drops with the addition of 0.02 mg·mL-1 phenylmercuric acetate met the A standard for bacteriostatic efficacy,while those with the addition of 0.5 mg·mL-1 ethyl hydroxy-benzoate met the B standard for bacteriostatic efficacy.Some chloramphenicol eye drops with the addition of 0.03 mg·mL-1 benzalkonium bromide or 0.25-0.3 mg·mL-1 ethyl hydroxybenzoate did not meet the B standard for bacteriostatic efficacy.Conclusion:This evalua-tion identified inappropriate types or concentrations of bacteriostatic agents in some chloramphenicol eye drops.Therefore,further improvement of the formulation is needed to improve the safety of chloramphenicol eye drops.