Abstract: For improving the sizing performance of starch,nano-auxiliaries were incorporated into the starch,and the promoting effect of nano-auxiliaries to sizing with starch was investigated.The influences of chemical composition and particle size of nanoparticles upon the sizing behavior of the starch were evaluated through comparative experiments.It was discovered that the abrasion resistance of the sized yarns increases and the hairiness reduces through blending the nanoparticles with starch pastes.Moreover,the chemical composition and particle size of the nanoparticles show evident effect upon the performance of the sized cotton yarns.SiO2 is superior to TiO2in enhancing sizing behavior.The smaller the particle size,the better the promoting effect to starch sizing.