Objective To investigate the value of the combined test in the diagnosis of thalassemia and iron deficiency anemia (IDA) .Methods From August 2013 to February 2015 ,36 patients with thalassemia ,34 patients with IDA ,and 30 healthy people who had undergone physical examination were enrolled in the study .The blood samples of those people were tested ,and items of the combined test included content of red blood cell volume(MCA) ,red blood cell volume distribution width(RDW) ,hemoglobin(Hb) electrophoresis and red blood cell(RBC) .Results The patients with IDA or thalassemia had reduced MCA and RBC fragile ,pa‐tients with IDA had increased RDW ,and patients with thalassemia had increased HbA2 ,compared with the control group the differ‐ences were all statistically significant(P<0 .05) .The sensitivity of RDW to IDA was 70 .6% ,and to thalassemia was 77 .8% ,the difference was not statistically significant (P> 0 .05) .The sensitivities of MCV ,Hb electrophoresis ,RBC fragility to thalassemia were 97 .2% ,88 .9% ,77 .8% respectively ,and the specificity were 80 .0% ,90 .0% ,83 .3% respectively .The sensitivities of MCA test combined with Hb electrophoresis ,hemoglobin electrophoresis combined with RBC brittleness test and parallel combined test of MCA ,Hb electrophoresis and RBC brittleness to thalassemia were 100 .0% ,97 .2% ,100 .0% respectively ,which were significantly higher than those of single tests ;the specificities were 96 .7% ,100 .0% and 100 .0% respectively ,which were significantly higher than those of single tests ;the differences were statistically significant(P<0 .05) .Conclusion The application of hematological pa‐rameters ,Hb and RBC in the diagnosis of anemia and IDA could significantly improve the diagnostic accuracy ,and it is worthy of popularization and application .