This study was carried out to compare the bioavailability of $Ceclex^{(R)}$ (test drug, cefaclor 250 mg/capsule) with that of $Ceclor^{(R)}$ (reference drug) and to estimate the pharmacokinetic parameters of cefaclor in healthy Korean adult. The bioavailability was examined on 20 healthy volunteers who received a single dose (250 mg) of each drug in the fasting state in a randomized balanced 2-way crossover design. After dosing, blood samples were collected for a period of 6hours. Plasma concentrations of cefaclor were determined using HPLC with UV detection. The pharmacokinetic parameters $(AUC_{0-6hr},;C_{max},;T_{max},;AUC_{int},;K_e,;t_{1/2},;Vd)$ F, and CL/F) were calculated with non-compartmental pharmacokinetic analysis. The ANOVA test was utilized for the statistical analysis of the $T_{max},;log-transformed;AUC_{0-6hr};log-transformed;C_{max},;t_{l/2},;V_d/F$, and CL/F. The ratios of geometric means of AUC0-6hr and $C_{max}$ between test drug and reference drug were $103.2\%;(6.74;{mu}g{cdot}hr/ml;vs;6.53{pm}g{cdot}hr/ml);and;100.4\%;(4.85;{mu}gml;vs;4.82;{mu}g/ml)$, respectively. The $T_{max}$ of test drug and reference drug were $0.9pm0.38;hr;and;0.83pm0.34$ hrs, respectively. The $90\%$ confidence intervals of mean difference of logarithmic transformed $AUC_{0-6h},;and;C_{max}$ were log $0.98{sim}log$ 1.08 and log $0.88{sim}log1.15$, respectively. It shows that the bioavailability of test drug is equivalent with that of reference drug. The estimated half-life of this study was longer $(1.21pm0.27;hrs;vs;0.5-1;hr)$, the Vd/F was larger $(68.89pm25.72L$ vs 24.9L), and the CL/F was higher $(38.62pm7.09;L/hr$ vs 24.9 L/hr) than the previously reported values.