This study aims to determine the effect of red sugarcane mordant on dyeing natural dyes using cotton and using natural dyes of kesumba seeds (Bixa Orellana L). type of experimental research. The data used is primary data generated from 15 panelists to see the light and dark and evenness of color. The data collection method used a questionnaire compiled on a Likert scale and the answer choices were a Rating Scale. The collected data was processed and analyzed using the Friedman K-related sample test. dark light and evenness of color produced without the use of mordant that is the category of light and fairly even. And dark light and evenness of color produced using red sugar cane mordant, namely the category of less light and even. Analysis of the Friedman K-related sample test for dark light and evenness of color, the data obtained is 0.000, smaller than the significant level of 0.05, which means Ho is rejected. From the difference in color, it can be concluded that the effect of red sugar cane mordant on cotton using natural dyes from kesumba seeds (Bixa Orellana L) is significant.