Abstract: Objective: To analyze the difference of serological characteristics and therapeutic effect of blood transfusion between thalassemia and aplastic anemia (AA) patients after transfusion of RBC with different Rh antigens,and guide the clinical use of blood in the patients with these two diseases.Method: A total of 106 patients with thalassemia diagnosed and treated in our hospital from January 2015 to December 2019 were selected,including 61 males and 45 females,and 94 AA patients,including 51 males and 43 females.According to the matching degree and disease category of Rh antigen between the recipient and the donor,all patients were divided into Rh antigen complete matching group,Rh antigen partial matching group and Rh antigen random group.The differences of the positive rate of irregular antibody,the positive rate of direct anti human globulin test (DAT), the rate of adverse transfusion reaction and the efficiency of transfusion were compared and analyzed statistically.Result: There was no significant difference in the ratio of male to female in the two diseases (χ²=0.219,P＞0.05). The main irregular antibody was Rh blood group system.The positive rates of irregular antibody and DAT in the patients with aplastic anemia were lower than those in the patients with Rh antigen,and the difference was statistically significant (χ²=7.433;χ²=3.941,P＜0.05). The efficiency of blood transfusion in Rh antigen matched group was higher than that in Rh antigen partial matched group and Rh antigen random group,the difference was statistically significant (χ²=5.453;χ²=6.717,P＜0.05). There was no significant difference in the rate of adverse transfusion reaction among the groups (χ²=0.656,P＞0.05); there was no significant difference in the rate of irregular antibody,DAT,adverse transfusion reaction and transfusion efficiency among the groups of AA patients (χ²=0.180-5.241,P＞0.05). The positive rates of irregular antibody and DAT in patients with thalassemia were higher than those in patients with AA (χ²=4.318;χ²=5.572,P＜0.05). The blood transfusion efficiency of AA patients was higher than that of globin producing anemia,the difference was statistically significant (χ²=13.798,＜0.05). There was no significant difference in adverse transfusion reaction rate between the two diseases (χ²=0.004,P＞0.05). Conclusion: Patients with thalassemia should try to choose ABO and Rh anti-matched RBC infusions to reduce the production of alloantibodies.AA patients can only choose ABO same blood transfusion,which can reduce blood screening costs and ensure blood transfusion effectiveness.