A special dwarf mutant rice CHA-1,obtained by space mutation,was a stabile and inherited rice material.Genetic analysis of the height showed that the new mutant gene h(named as h temporarily) from CHA-1 was a major recessive gene which linked with sd-1 in a certain extent.The two genes had complementary interaction and controlled the dwarf trait of CHA-1 together;The dwarf gene h was located on chromosome 1 linked with SSR marker RM302 and the genetic distance was 5.1 cM.