Abstract: The effect of modifier amount,NaOH concentration,treating temperature,and duration of treatment on the dyeing K/S value of the cationized cotton fabric was researched when cationic modification of the cotton fabric was implemented with polyepichlorohydrin-amine(PECH-amine).The appropriate amount of salt and alkali for dyeing the modified cotton fabric black was discussed,and a comparison of the dyed fabrics of the modified and unmodified was made in terms of blackening,dye up-take,K/S value,and color fastness.The results demonstrate that the cationized cotton fabrics after being dyed black have excellent blackening,considerable improvement in K/S value and dye up-take,and better washing and rubbing fastness.