Mutant is an important material for investigating gene function of plant and developing new crop variety with good quality and high yield.In the study,three double-dwarf lines 08-408-12 and 08-19with dwarfism stably inheritedwere selected from the F6 progeny of 02428ha/02428.Plant height of three lines were 62.4±3.3cm,66.0±1.5cm and 67.5±1.7cm.Genetic analysis showed that the dwarfisms were controlled by 2 recessive genes,one gene was allelic to sd1,while the other one was a novel recessive semi dwarf gene sd-h(t),which was not allelic to sd1.These results provided a basis for mapping and molecular cloning and functional analysis of sd-h(t)