Thalassemia is a group of the most common human monogenic disorders. According to the World Health Organization, at least 7% of the population worldwide carries thalassemia associated genes. This disease is mainly distributed in Africa, Mediterranean, Southeast Asia and other tropical and subtropical regions. Hemolytic anemia caused by thalassemia is really harmful to human health. So it is of great importance to investigate the gene prevalence and spectrum of thalassemia in several areas with high incidences all over the world for the disease prevention, diagnosis and treatment. In this paper, we reviewed the research progress in molecular epidemiological analysis of thalassemias in multiple regions.