OBJECTIVE To study the bioequivalence of methylprednisolone (MP) tablets in healthy volunteers.METHOD A rapid and sensitive RP-HPLC assay was modified for the determination of the drug levels in plasma. In a randomized two-way crossover design, 40 mg single dose po domestic (B) and imported (A, MedrolTM) MP tablets, respectively, were given to 18 male healthy volunteers. The parameters were estimated by non-compartment model with a statistic analysis of ANOVA and two one-side t-test.RESULTS The tmax,cmax,t1/2 and AUC0~∞ of tablet-B and-A were (1.9±0.5) h and (2.1±0.5) h, (597.6±119.8 ) ng*mL-1 and (572.6±121.7) ng*mL-1,(2.2±0.4) h and (2.3±0.4) h,(2528.4±558.8) h*ng*mL-1 and (2571.2±647.4) h*ng*mL-1,respectively.The mean relative bioavailability of the tablet-B vs A was 99.62%. There was no significant difference between the two products.CONCLUSION The results suggested that these two products were bioequivalent.