Abstract: Evenness is an important factor in yarn appearance evaluation, different from the spun yarn, the mass evenness of textured yarn has nothing to do with its appearance evenness. A series of unifactor experiments concerning several parameters of filaments and texturing were designed as the first step heading for the final designing and controlling of textured yarn’s structure and properties. It has been proved that the evenness of the differential shrinkage filaments air-jet textured yarn can be controlled effectually by the different filament or multi-filament linear density, air-jet texturing and differential shrinkage parameters. The over feed and feeding method in air-texturing, the differential shrinkage rate and average shrinkage in differential shrinking can affect the CV value of air-jet textured yarn remarkably.