To investigate the significance of GATA-2 and immunoglobulin heavy chain germline gene C( micro ) (IgH germline gene C( micro )) expression and coexpression in various leukemia cells, GATA-2 and IgH germline gene C( micro ) mRNA in bone marrow and peripheral blood cells from 63 leukemia patients were detected by reverse transcription-polymerase chain reaction (RT-PCR). No GATA-2 or IgH germline gene C( micro ) mRNA were detected in normal bone marrow and peripheral blood. GATA-2 mRNA were be detected in 91.3% patients with acute myeloid leukemia (AML), 75% patients with acute lymphoblastic leukemia (ALL) as well as 83.3% patients with chronic myeloid leukemia (CML-CP); IgH germline gene C( micro ) mRNA were be identified in 47.8% AML, 41.6% ALL, as well as 5.6% CML-CP. All patients with CML-AP and CML-BC expressed GATA-2 mRNA and partly expressed IgH germline gene C( micro ) mRNA. 47.8% AML and 41.6% ALL patients coexpressed GATA-2 and IgH germline gene C( micro ) mRNA. GATA-2(+) IgH germline gene C( micro )(+) cells of AML and ALL were mainly HLA-DR positive. As aberration of the transcription factors, GATA-2 and germline IgH germline gene C( micro ) gene might been linked to leukemogenesis. Various expression of GATA-2 and germline IgH germline gene C( micro ) gene in leukemia might correlated with the heterogeneous differentiation level of leukemia cells. The fact that leukemia with GATA-2(+) IgH germline gene C( micro )(+) coexpression indicated multilineage impairment of hematopoietic cells.