In this study, the main purpose was to evaluate the bioequivalence of two thioctic acid tablests, Thioctacid HR tablet(Bukwang Pharm. Co., Ltd.) and Daewon thioctic acid HR tablet 600 mg(Daewon Pharm. Co., Ltd.), according to the guidelines of Korea Food and Drug Administration(KFDA). Twenty-four, healthy Korean volunteers were divided into two groups, randomized and treated by $2{ imes}2$ crossover study. After the administration of one thioctic acid tablet containing 600 mg thioctic acid, blood samples were taken until 8 hr after the oral administration. LC-MS/MS was applied to determination of thioctic acid, and we calculated the $AUC_t,;C_{max},;T_{max}$ from the plasma concentration-time data. Analysis of variance(ANOVA) was carried out using logarithmically transformed $AUC_t;and;C_{max}$. No significant sequence effect was found for all of the bioavailability parameters indicating that the crossover design was properly performed. The 90% confidence intervals of the $AUC_t$ ratio and the $C_{max}$ ratio for Daewon thioctic acid tablet 600 mg/Thioctacid HR were log 0.9877$sim$log 1.1938 and log 0.8169$sim$log 1.2237, respectively. These values were within the acceptable bioequivalence intervals of log 0.80$sim$log 1.25, recommended by KFDA. In all of these results we concluded that Daewon thioctic acid tablet 600 mg was bioequivalent to Thioctacid HR tablet, in terms of rate and extent of absorption.