This study investigated the effects of mashed maesil and maesil extract on Kimchi during fermentation. The mashed maesil and maesil extract were added at 5% of the weight of salted cabbages to the Kimchi sauce, and then physiochemical and sensory characteristics were examined over 28 days of fermentation at 4$^{circ}C$. During the entire fermentation process, the mashed maesil Kimchi had a consistent pH of 4.4 to 4.2, and the mashed maesil controlled fermentation better than the maesil extract. The mashed maesil Kimchi had the lowest acidity ($0.43{pm}0.01{sim}0.42{pm}0.01$), despite showing a similar pH level to the maesil extract Kimchi. The mashed maesil Kimchi presented the highest hardness level. And in the early stage of fermentation the control Kimchi had the lowest hardness; however, at the end of storage, hardness increased in every Kimchi and no differences were shown. In terms of color value changes, the L-values of every Kimchi increased as the fermentation period increased; but on the $28^{th}$ and final day of fermentation L-values had decreased in all groups. The group with mashed maesil had the highest a-value, but there were no significant differences in b-values among the groups. In evaluating sensory characteristics and acceptability of flavor, the maesil extract Kimchi was higher in intensity with regard to sourness, umami taste, sweetuess, maesil taste, carbonated taste, and fresh taste; it also had higher overall acceptability. Therefore, a fixed amount of maesil extract(5%) can be added to Kimchi with good affects on quality, by controlling fermentation and increasing flavor.