 The investigation found that dyeing cotton fabric with natural dye extracted from purple corncob using cationic agent 3-chloro-2-hydroxapropyl trimethylammonium chloride, CHTAC, at a concentration of 125gL and dyeing at 100 degrees Celsius for 30 minutes in a pH 9-adjusted dye bath resulted in maximum color yield. Post-mordanting with Alk, SO4, 2, CUSO4, FESO4, and Galnut-enhanced KS values and slightly improved light fastness but reduced wash fastness from excellent to fair level, except for CUSO4. Meanwhile, mordanting with Galnut increased acid and alkaline perspiration fastness from poor and fair to good level. This article was authored by Mornhan Naktatham, Poofer Sombung, Nutsaranamal, and others.