Abstract: OBJECTIVE To explore the life span of red blood cell(RBC) in patients with myelodysplastic syndrome(MDS) and the effect of amifostine on the life span of RBC. METHODS Retrospective analysis of clinical data of 81 patients with MDS from January 2017 to July 2018 in department of hematology in Zhejiang Provincial Hospital of TCM, divided into amifostine treatment group(49 cases) and supportive treatment group(32 cases). In the same period, 9 healthy volunteers were used as normal controls. The endogenous Breath Carbon Monoxide(CO) test was used to measure the life span of RBC in patients and volunteers. The life span of RBC in patients with MDS and the effect of amifostine on life span of RBC were explored. RESULTS The mean life span of RBC of 81 patients with initial MDS(no blood transfusion support) was (33.41±10.96)d, which was significantly shorter than that in the normal control group(121.11±32.59)d (P<0.01). In the amifostine treatment group, one case achieved partial remission, 13 cases achieved hematologic improvement(HI), 12 cases achieved stable disease(SD), the overall response(ORR) was 53.1%. The life span of RBC in patients with MDS after treatment was (42.24±12.99)d, which was significantly longer than that before treatment (P<0.01). In the supportive treatment group, 2 cases achieved HI, and 9 cases achieved SD, the ORR was 34.4%, and the life span of RBC was (34.53±7.50)d, which was not significantly improved compared with before treatment. Statistical analysis of the efficacy of treatment showed that, the HI patients with the life span of RBC was (45.92±9.24)d. It was significantly shorter than the normal control group(P<0.01), and it was significantly longer than before treatment(P<0.01). There was no statistical significance of RBC life span in other patients before and after treatment. CONCLUSION The life span of RBC is shortened in patients with MDS, which can be improved after treatment with amifostine.