Abstract: Aiming at the problem of low dye-uptake and poor color fastness of natural dyes on cotton fabrics, the technology of non-reactive modification on cotton with cationic surfactants was studied. The effect of modifier type, modifier concentration, treating temperature, treating pH value and duration of treatment on the dyeing K/S value was researched; the physical mechanical properties of cotton pre and post modifying , level dyeing property and color fastness was also analysis. The results demonstrate that the cationized cotton fabrics still remain its excellent whiteness、strength and hygroscopicity; the dyed cotton with natural dyes have considerable improvement in K/S value，and better level dyeing property, as well as color fastness.