Abstract: The particle morphology,A/B starch content,relative crystallinity of starch,protein component and molecular weight,and dynamic mechanical property of wheat flour with different particle size obtained by sieving were analyzed in the present study.The results showed that with the decrease of particle size of wheat flour,the particle size and quantity of endosperm block mass decreased;the starch particle and stroma fragments increased;albumin content decreased;globulin content increased;gliadin content increased firstly and then decreased;glutenin had no significant change;a part of small molecular weight (mainly in albumin and globulin region) disappeared.The content of A starch and the relative crystallinity of starch were higher in wheat flour with smaller particle size.In wheat flour with 180~200 mesh range,endosperm block mass and starch particle were uniformly distributed;gliadin content was higher;the ratio of A/B starch was close to that of original wheat flour;the afforded patch had higher energy storage modulus and loss modulus.The types and contents of starch and proteins in wheat flour with different particle size had significant difference,which would have different effects on the various wheat flour products.