Objective:To establish a LC-MS/MS method for assessment of pharmacokinetics of dispersible tablet of roxithromycin and ambroxol hydrochloride (each containing roxithromycin 150 mg,ambroxol hydrochloride 30 mg). Methods:Each of 12 healthy Chinese volunteers was given a single oral dose of one tablet. Plasma samples were collected at 72 h post-administration and the concentrations were determined by LC-MS/MS. The pharmacokinetic parameters were calculated by DAS software. Results:The main pharmacokinetic parameters of Cmax,Tmax,t1/2z,MRT,AUC0-τ,CLz/F and Vz/F for roxithromycin were (6.99±1.55) μg/ml,(2.04±0.94) h,(13.30±2.56) h,(14.31±2.51) h,(84.56±26.20) h·μg/ml,(1.88± 0.51)L/h and (35.06±8.68)L,respectively;and those for ambroxol hydrochloride were (53.91±22.41) ng/ml,(1.96±0.66) h,(8.24±2.01) h,(7.96±0.47) h,(447.98.±138.95) h·ng/ml,(61.85±14.79)L/h and(724.42±214.86)L,respectively. Conclusion:The established LC-MS/MS method is selective,sensitive and reliable for the pharmacokinetic study of the dispersible tablet of roxithromycin and ambroxol hydrochloride.