Results: Epidemiological factors: there are 66 cases of major Thalassemia with splenectomy, 10, 6% patients under 6 year old, 89, 4% above 6 year old. Patients from An Giang, Bạc Liêu, Đồng Nai, Bến Tre, Bình Thuận provinces and Ho Chi Minh City got the high ratio.