Abstract：Chang S is a new rice thermo-sensitive genic male sterile （TGMS） line obtained from the offsprings of the cross between Oryza rufipogon L. and indica Zhenzhu’ai. The sterility segregation and its genetic pattern of Chang S was analyzed based on the investigation of the fertility of the individuals in F1and F2 populations from the crosses of Chang S and indica conventional varieties such as Zhongzhe B ，R608， and so on under natural long day-length and high temperature conditions in Ji’an in 2011. The results indicated that the sterility of Chang S was controlled by one pair of recessive nuclear genes. Fertilities of F1 generations of the crosses between Chang S and other five photo or thermo-sensitive genic male sterile（P﹠TGMS）lines such as HN5S，C815S，Guangzhan 63S，Xiangling 628S and HD9802S were investigated under the same natural conditions in Ji’an in 2011. The results showed that the sterility gene in Chang S was nonallelic to that in the photo-sensitive genic male sterile（PGMS）line HN5S，and allelic to those in thermo-sensitive genic male sterile（TGMS）lines such as C815S，Guangzhan 63S，Xiangling 628S and HD9802S.