A simple and sensitive high performance liquid chromatographic method to quantitate ${alpha}-keto$ acids in serum and urine was investigated. ${alpha}-Keto$ acids react with 1,2-diamino-4,5-methylenedioxybenzene (DMB) in the presence of 2-mercapto-ethanol and sodium hydrogen sulfite to form highly fluorescent derivatives, substituted 6,7-methylenedioxyquinoxalinol. The derivatization procedure was performed in water bath at $100^{circ}C$, and completed within 50 min. By the use of a reversed-phase column and multi-step gradient with two solvents, a mixture containing twelve of these derivatives were efficiently resolved within 35 minutes. The optimal wavelengh of the fluorescence detector are ${lambda}_{ex}=364;nm$ and ${lambda}_{em}=445;nm$. The quantitation of the individual ${alpha}-Keto$ acids was reproducible with relative standard deviation of $3.0{sim}7.9%$ and had a detection limits of $10{sim}60$ fmol, except for p-hydroxyphenylpyruvic acid (960 fmol).