Chronic anemia patients are generally appropriate to transfuse 2 units of red blood cells every 2~4 weeks, the following from the common several chronic anemic diseases to elucidate. 1. Aplastic anemia: need long-term transfusion, can be transfused with suspended red blood cells or concentrated red blood cells. Usually transfused within 12 hours after preparation, should not be saved. 2. Iron deficiency anemia: iron supplementation is sufficient in general, such as ferrous succinate, etc., and suspension red blood cells or concentrated red blood cells can be transfused appropriately in case of severe anemia. 3. Megaloblastic anemia: generally do not need transfusion treatment, need to supplement folic acid and vitamin B₁₂. If the condition is serious, suspension of red blood cells may be appropriate. 4. Thalassemia: those with severe condition should be transfused as early as possible. 5. Autoimmune hemolytic anemia: if there is an indication for blood transfusion, ABO blood type should be selected, the patient’s serum and the donor’s red blood cells with the weakest cross-match reaction of red blood cell transfusion. If the condition is more urgent, O-type washed red blood cells can be chosen. The speed of blood transfusion should be slow, generally 100ml of red blood cells should be transfused at one time. Chronic anemia can also be seen in other cases, the condition is different, the transfusion treatment plan is different, it is recommended to consult a doctor in time, under the guidance of the doctor to correct anemia.