Abstract: Objective: To study the determination of the acute leukemia(AL) immunotyping and the bone marrow's(BM) metastatic tumor cell.Methods: The immunotyping of 39 cases of acute leukemia and 10 cases of BM metastatic tumor cell were detected by immunocytochemistry,with 8 routine CD markers and 2 kinds of CK antibodies.Results: The immunotyping and FAB morphological classification manifested a high coincidental rate,but there existed CD antigen's cross and reversal phenomena in lymphatic system and bone marrow system.The 3 cases of acute leukemia difficult to type with FAB morphology were identified with immunocytochemistry.The 10 cases of BM metastatic tumor cell were also diagnosed with the immunocytochemistry.Conclusions: The insufficiency in leukemia typing with FAB morphology,especially the acute leukemia and bone marrow metastatic tumor cell which are difficult to type with FAB morphology,can be supplemented with immunocytochemistry.