The purpose of this study was to investigate the effects of preheating and salt concentration on the fermentation rate and firmness of cucumber kimchi, and the relationship between firmness and the contents of pectin fractions, hemicellulose and cellulose during fermentation. For this purpose, pH, acidity, firmness and the contents of pectic fractions, hemicellulose and cellulose were studied. 1. The changes of pH and titratable acidity indicated that preheating and high salt concentration delayed the fermentation rate in cucumber kimchi. 2. After 9 days, preheated cucumber kimchi was firmer than nonpreheated cucumber kimchi. 3. During fermentation, the cucumber kimchi fermented at 5% NaCl was firmer than that femented at 2% NaCl. 4. After 9 days, preheated cucumber kimchi was higher in insoluble pectin (HCISP)content and lower in soluble pectin (HWSP & HXSP) content than nonpreheated cucumberkimchi and hese results in accord with those of firmness measurements. 5. During fermentation, the cucumber kimchi fermented at 5% NaCl was higher in insoluble pectin content and lower in soluble pectin content than nonpreheated cucumber kimchi, and these results were in accord with those of firmness measurement. 6. During fermentation, cellulose content decreased.