Abstract: Objective Tostudy the cell morphologic and immunophenotypic characteristics of patients with acute promyelocytic leukemia (APL). Methods Flowcytometry instrument immunofluorescence technique was usedtodetect the immune phenotype of leukemic cells in 82 patients with APL, and bone marrowcell morphology inspection was alsoapplied. Results The proportion of abnormal promyelocyte detectedby morphologic examination was 50.5%- 94.5%, the proportion of abnormal promyelocyte detectedby CD45/SSC gating was 45.6%- 88.2%. The antigen positive expression rate and the average ratioof positive cells were as follows: CD33 (100%, 90.2%), CD13 (100%, 85.3%), CD9 (85.4%, 68.2%), CD64 (91.5%, 67.4%), CD117 (65.9%, 56.4%), CD2 (11.0%, 36.2%), CD11b (18.3%, 30.5%), CD16 (0.0%, 0.0%), CD19 (3.7%, 26.3%), CD15 (9.8%, 44.6%), CD4 (0.0%, 0.0%), CD56 (17.1%, 41.7%), CD34 (9.8%, 40.4%), CD3 (0.0%, 0.0%), CD7 (4.9%, 34.2%), CD10 (0.0%, 0.0%), CD14 (0.0%, 0.0%), CD20 (0.0%, 0.0%.), HLA-DR (12.2%, 42.4%). CD2 and CD56 antigen expression was significantly higher in CD34⁺ and /or HLA-DR⁺ groupthan in CD34^- and HLA-DR^- group(P＜ 0.05). M3a type CD117 positive antigen expression rate was significantly higher than M3v type (P＜ 0.05), M3v type CD34 positive antigen expression rate was significantly higher than M3a and M3b type (P＜ 0.01). Conclusion Bone marrowcell morphology is the basis of the diagnosis of APL, and it will be helpful in improving the diagnosis accuracy and analysis of the source of leukemia cells if combing with immunophenotype.