Abstract: 291S was a wheat male-sterile mutant which discovered by the author in common wheat new strain Xinong 291. In this paper, the characteristics of fertility alteration, male abortion and the inheritance of sterility on 291S were analyzed preliminarily. The interval sowing experiments showed that 291S was a photo-thermo-sensitive male sterile line, which showed part fertile under short-day and low-temperature conditions when autumn sowing, showed high sterile under long-day and high-temperature conditions when spring sowing. The self-multiplication ability and sterility of 291S can be improved through selection effectively. The pistillody of stamens of 291S could be induced under certain photoperiod and temperature condition. I2-KI staining of pollens showed the abortive pollen of 291S in sterile period was mainly the spherical abortion type. Genetic analysis showed 291S might be a genic male sterile line, its sterility was controlled by a major recessive nuclear gene and was influenced by other minor genes. The 291S type photo-thermo-sensitive male sterile line has good application prospect in the two-line hybrid wheat breeding system.