With the popularity of flow cytometry, the classification of leukemia become more detailed. Myeloid/natural killer cell precursor acute leukemia and myeloid/natural killer cell acute leukemias are generally recognized as two kinds of rare leukemias and have poor prognosis. The cells expressed both myeloid and lymphatic antigens in these two leukemia and can not be diagnosed by morphology. The only basis to make a definite diagnosis is their unique Immunophenotyping. The role of CD7 and CD56 in these two leukemia are compelling, in the other hand, as the progress of cell differentiation research, there are many new awareness of NK cell differentiation. In this article, the biological origin, clinical manifestation, diagnosis, treatment and the role of CD7 and CD56 in these two leukemia are briefly summarized.