Shaannong78, a wheat variety with stripe rust resistance, was crossed with susceptible cultivar Mingxian169 as the female. The F1 progeny was self-mated to produce F2 progeny and backcrossed with Mingxian169 to produce BC1 progeny. In air-conditioned greenhouse，seedlings of the F1, F2, BC1 progenies and their parents were inoculated with the prevalent races CY31 and CY32 of Puccinia striiformis respectively. The phenotypes of the F1, F2, and BC1 plants were analyzed for resistance to two races Results showed that Shaannong78 has one recessive gene for resistance to race CY31 and two recessive genes for resistance by complementary action to race CY32.