Changes of chemical and oxidative/antioxidative characteristics chlorophylls(CHLs) and their derivatives in the model system of mustard leaf kimchi(MLK) were investigated. During fermentation of MLK(at 15oC, for 25days, 2.3$pm$ 0.1% salt content) pH and total acidity were decreased/increased from 5.6 and 0.4%(initial day) to 3.6 and 1.07%(final day) resceptively. Activities of lipoxygenase and peroxidase were decreased gradually, however, these of chlorophyllase was increased in the first 10 days of fermentation. CHLs of MLK in the initial stage of fermentation were degraded rapidly and all CHLs and chlorophyllides were converted to pheophytins and pheophorbides in the final stage. Deg radation effects of CHLs(a & b) and their derivatives(pheophytins a & b) fractionated from MLK and carotene on the autoxidation and lipoxygenase oxidation of linoleic acid were observed, and also stronger antioxidative activities of CHLs and pheophytins were shown in their autoxidation/enzymtic oxidation of linoleic acid.