Non deletion HbH disease is more severe than deletional HbH disease, have clinical signs similar with beta thalassemia major. Aim: Study about the clinical features and laboratory testings of 6 HbH patients affected with SEA/HbCs mutation on a globin gene. Results: 6/6 patients have severe anemia, slenomegalies, 5/6 patients need blood transfusion like beta thalassemia major. 1/6 patient is combination between HbH and beta thalassemia (CD17), no need blood transfusion. 6/6 patients has low MCV, HbH is 6-16 percent. Conclusion: HbH due to SEA/HbCs muations has the clinical features similar with beta thalassemia major, need more understanding for genetics counselling and prenatal diagnosis.