The application of Dongchimi liquid into Naengmyon broth for the improved eating quality of Naengmyon was scientifically explored by reviewing the quality properties of the product. Primarily, the optimum fermentation conditions for Dongchimi from which the liquid portion was extracted were pursued and the optimum mixing ratio was sought on the basis of sensory and microbiological properties of the product. The liquid portions which had been periodically extracted from Dongchimi at intervals of two or five days during fermentation at $10^{\circ}C$ were added to Naengmyon broth. The treatments were prepared with three levels, namely, basic broth only('A') and the ratios of 3:7(v/v, 'B') and 5:5(v/v, 'C') of Dongchimi liquid and basic broth, respectively. According to assessments of Dongchimi liquid on taste and intensity based on sensory analyses, the organoleptic factors such as color, smell, sour taste, carbonated taste, and overall acceptability were given higher values from day 11 to day 17 in all items. As for the assessment of Dongchimi liquid on intensity, color, sour odor, moldy odor, and carbonated taste have shown the increasing scores during with high intensities while those for clearness has stayed low. Most of the phenomena observed from the Naengmyon broth substituted with $30\%$ (Treatment 'A') and $50\%$ (Treatment 'B') of Dongchimi liquids with different storage periods ensued much of the previous fermentation pattern of Dongchimi itself. Organoleptic assessment on taste and its intensity showed that better(the best) scores could be obtained at between day 16$\~$25(17) and 13$\~$20(15) for Treatments A and B, respectively. The intensity scores of taste for color, smell, carbonated taste, sour taste, and mouthfeel were increased while those for clearness, palatability, and meaty ones were decreased with lapse of fermentation. The numbers of total cell and lactic acid bacterial counts of Dongchimi has increased until day 13 and then decreased in the later stages. Total cell count and lactic acid bacterial counts of Naengmyon broth also increased until the 13th day and then they began to decrease. It was also proven that slightly over-ripened Dongchimi liquid was more preferable for adding into Naengmyon broth. Granting the optimum ripening period of Dongchimi liquid itself to be 13 days, both Treatment A and Treatment B were evenly favored using Dongchimi liquids slightly over-ripened at days 13 to 17. However, Treatment A was more favored than Treatment B when Dongchimi liquid over-ripened for 20 to 26 days was used.