We characterized the character impact compounds of flavors of the fermented Korean soy sauce manufactured with both the traditional and the improved Meju made with different strains. The whole flavor samples were obtained by extracting each volatile flavor phase from both the traditional and the improved soy sauce. To get more detailed information, each whole volatile flavor was further fractionated into the basic, acidic, phenolic and neutral fractions. Each separated peak from the whole and fractionated flavor samples on gas chromatogram was identified by GC/MS and Kovat s retention index, and likewise the aroma of each peak was investigated by a sniffing test with the exercised panel. We were able to identify 15 groups of ingredients with the characteristic soy sauce aroma from the soy sauce made with the traditional Meju and 6 groups from the soy sauce manufactured with the improved Meju made with Aspergillus oryzae. The character impact compounds the two soy sauces were different from each other.