Abstract: OBJECTIVE To establish an HPLC method for simultaneous determination of 4 categories and 9 species common bacteriostats which might be added into naphazoline hydrochloride nasal drops, including thimerosal, ethylparaben, sodium benzoate, methylparaben, propylparaben, butylparaben, sorbic acid, benzalkonium chloride, benzalkonium bromide. METHODS The analysis was performed on Ultimate XB-C₁₈ column(4.6 mm×250 mm, 5 μm) at 35℃, eluted with a gradient program using acetonitrile(A)-0.1 mol·L^-1 sodium phosphate monobasic(pH was adjusted to 3.7 with phosphoric acid) as the mobile phase. The flow rate was 1.0 mL·min^-1, the detection wavelength was 222 nm, and sample was stored at 5℃. RESULTS Under the above conditions, 9 bacteriostats were separated completely. The average recoveries of the 9 components were between 98.2%-100.6%, with RSDs of 0.5%-1.5%. The contents of thimerosal, benzalkonium bromide, ethylparaben and sodium benzoate were detected in 30 batches of naphazoline hydrochloride nasal drops. CONCLUSION The method is suitable to evaluate the quality of bacteriostats in naphazoline hydrochloride nasal drops.