The objective of this study is to research the physical property of mercerized-cotton treated with various alkalies. The types of alkalies were LiOH, NaOH, and KOH. The treatment conditions for mercerization were various temperatures and concentrations. The effects of mercerization after alkali treatment were estimated with the changes of structure, tensile strength, dyeability, and light stability. Experimental results showed the tensile strength of mercerized-cotton with KOH was higher than NaOH or LiOH. And the dyeability of mercerized-cotton with KOH or LiOH was better than NaOH. The light stability of mercerized-cotton was affected more by alkali concentration than by alkali type.