Thalassemia is the most common inherited diseases in southern China.However, this disorder is usually ignored by health system in Sichuan Province due to lack of epidemiological data.To provide basic epidemiology information for thalassemia screening, genetic counseling and prenatal diagnosis (PND) in Chengdu region, a total of 3,262 healthy subjects were screened by completed blood cell (CBC) count, reverse dot blot (RDB) gene chip.Our results presented that heterozygote frequency of thalassemia was 3.31% (108/3262), of which 2.21% (72/3262) carried α-thalassemia and 1.16% (38/3262) were β-thalassemia carriers.Four types of α-thalassemia mutation, the most prevalent being the--SEA (68.06%), followed by-α3.7 (rightward) (25%), Hb Quong Sze (HBA2: c.377T>C) (4.17%) and-α3.7 (leftward) (2.78%).The six point mutations identified in the ββ-thalassemia carriers were: HBB: c.316-197C>T (34.21%), HBB: c.52A>T (28.95%), HBB:c.126_129delCTTT (23.68%), HBB: c.-78A>G (7.89%), HBB: c.-79A>G (2.63%) and HBB: c.84_85insc (2.63%).This was the first detail molecular epidemiological survey of thalassemia in Chengdu region of Sichuan province, Peoples Republic of China (PRC).