A bioequivalence study of CKD $Cefaclor^{(R)}$ capsule (Chong Kun Dang Pharm Co., Ltd) to $Ceclor^{(R)}$ capsule (Lilly Korea Co., Ltd.) was conducted according to the guidelines of Korea Food and Drug Administration (KFDA). Twenty four healthy male Korean volunteers received each medicine at the cefaclor dose of 250 mg in a $2{ imes}2$ crossover study. There was a one-week washout period between the doses. An improved high-performance liquid chromatorgraphy (HPLC) analytical method with UV detection was used to determine plasma cefaclor concentration in human volunteers for 8 hr after oral drug administration. The area under the plasma concentration-time curve from time zero to 8 hr ($AUC_{0-8hr}$) was calculated by the linear trapezoidal rule. the $C_{max}$ (maximum plasma drug concentration) and $T_{max}$ (time to reach $C_{max}$) were compiled from the plasma concentration-time data. Analysis of variance was carried out using logarithmically transformed $AUC_{0-8hr};and;C_{max}$. No significant sequence effect was found for all of the bioavailability parameters indicating that the cross-over design was properly performed. The $90{\%}$ confidence intervals of the $AUC_{0-8hr}$ ratio and the $C_{max}$ ratio for CKD $Cefaclor^{(R)}$ and $Ceclor^{(R)}$ were $0.9400{leq}{delta}{leq}1.0345$ and $0.8858{leq}{delta}{leq}1.1021$, respectively. These values were within the acceptable bioequivalence intervals of 0.80-1.25. Thus, our study demonstrated the of CKD $cefaclor^{(R)}$ capsule was bioequivalent to $Cefaclor^{(R)}$ capsule with respect to its bioavailability.