Objective To investigate the cell morphology and immune phenotypic characteristics in Uygur and Han patients with myelodysplastic syndrome (MDS) in Xinjiang Uygur Autonomous Region.Methods Bone marrow smears of 67 cases diagnosed as MDS were systematicly observed and recorded,flow cytometry (FCM) was used to test the immunophenotyping.Results There were abnormal hematopoiesis in different extent in granulocyte series,erythron series and megakaryocytic series of all patients.Occurence of pathological hematopoietic performance in Uygur patients with MDS was similar to that in Han,granulocyte series [52 cases (77.6 ％)] ＞megakaryocytic series [44 cases (65.7 ％)] ＞ erythrocyte series [36 cases (53.7 ％)],the differences in two groups were not significant (x2 values 1.02,0.30,0.02,respectively,all P ＞ 0.05).The changes type of pathological hematopoietic performance in two groups were similar,single garden nuclear megakaryocyte [36 cases (53.7 ％)],false Pelger nuclear anomaly granulocyte [36 cases (53.7 ％)],erythroid gigantic young cell change [33 cases (49.3 ％)],granulocyte cell particles reduced or absent [27 cases (40.3 ％)] etc.The result of FCM showed that along with the progressive change of RA/RAS to RAEB/RAEB-t,the expression ratios of mature CD15 were decreased,while the expression ratios of early stage CD117 and CD34 were raised gradually (x2 values 6.23,12.06,8.95,7.37,8.95,8.08,respectively,all P ＜ 0.05),the differences in two groups were not significant (x2 values 0.715,0.024,0.146,respectively,all P ＞ 0.05).Meanwhile,Uygur patients with MDS has great expression of CD56 and Han had HLA-DR,there were significantly differences in two groups (x2 values 3.91 and 3.90,respectively,both P ＜ 0.05).Conclusion Occurence of pathological hematopoietic performance in Uygur patients with MDS are similar to that in Han.Most MDSs has two or more levels of pathological hematopoietic performance.The differences of immunophenotype characteristics in two groups are partially significant and test of immunophenotype are helpful in the diagnosis,classification,prognosis of MDS.