Abstract In this study, reconstituted whole-wheat flour (WWF) samples of different particle sizes from U.S. soft white winter (median diameters: 164.0, 110.7 and 97.8 μm) and soft red winter (median diameters: 154.3, 112.8 and 99.9 μm) wheat cultivars were obtained by fine grinding of bran and shorts from roller milling and re-combining with the remaining fractions. Extensibility tests showed that reducing the particle size of WWF strengthened the gluten network of dough. Mixolab results indicated that reducing the particle size of WWF resulted in shorter development time and longer mixing stability of dough. Meanwhile, the starch hot-gel stability and retrogradation increased with the WWF particle size reduction. The Chinese southern-type steamed bread (STSB) making test showed that SB made from WWF of smaller particle size had a significantly larger specific volume than that made from WWF of larger particle size. C-cell analysis of the crumb grain of SB revealed that the grain cells became smaller with thinner cell walls as WWF particle size was reduced. These results indicate that reducing the particle size of WWF could improve the quality of Chinese STSB.