The einkorn wheat contains abundant resistance genes and is one of important resources for common wheat cultivar improvement. An einkorn wheat accession 3AA30 was proved to be resistant to wheat powdery mildew in Beijing. Genetic analysis showed that 3AA30 carries a recessive resistance gene, temporally designated ml3AA30. Five SSR markers (Xgwm6, Xcfd39, Xcfa2185, Xcfa2141, Xcfa2155) and two STS markers (Xmag2170, Xmag1491) on chromosome 5AL of wheat were found linked to ml3AA30 by bulked segregant analysis, and a genetic map of ml3AA30 was established. Based on the above result,powdery mildew resistance gene ml3AA30 was located on the long arm of wheat chromosome 5A. This result provides new materical for wheat powdery mildew resistance breeding program.