The heterosis of plant height and its components of hybrid bread wheat and the effect of Rht 3 gene were investigated in this paper. The results showed that all characters of hybrids had heterosis and heterobeltiosis, but their values varied among crosses and internodes; the heterosis and heterobeltiosis of length of basal internode were larger than those of other internodes and length of spike; there were less heterosis and heterobeltiosis for all characters in the hybrids from female parents with the Rht 3 gene than those in other hybrids. The Rht 3 gene increased the effects of lengths of second and third internodes and their heterosis on plant height and changed the relationships among the components in F₁ hybrid. In the combinations from Aline with the Rht 3 gene, the R Iines were much more important to determine the plant height and its components of their hybrids than A lines, and so, it was relatively easier for breeders to control these characters of hybrid vvheat.