Abstract： Objective To investigate the anti-inflammatory/immune modulatory effects of high-expressing membrane bound M-CSF-hematopoietic malignant cells on macrophages. Methods After coculturing RAW264.7 and murine macrophage cell line with Namalwa-M, a cell line stably expressing mM-CSF, and companing with Nainalwa-V, a cell line stably transfected with the empty vector as the control, flow cytometry was used to detect the expression of the marker of alternatively activated macrophages, CD206, and intracellular expression of IL-10, IL-12, IL-6 and TNF-α to study the immunophenotype of RAW264.7; phagocytic assays to investigate their functional activity in vitro. Results RAW264.7 cocultured with Namalwa-M consistently showed high-level expression of CD206, which indicated activities of these macrophage cells were increased. Furthermore, these RAW264.7 expressing high levels of IL-10, TNF-a and low levels of IL-12, IL-6, as determined by intracellular staining were suggested that the phagocytic activity was increased. Functionally, RAW264.7 cocultured with Namalwa-M showed a higher level of phagocytic activity. Conclusion Macrophage generated in vitro after cocultured with mM-CSF-expressing hematopoietic malignant cell line could be transformed into abnormal macrophage with an immunophenotype defined as IL-10-high, IL-12-low, IL-6-low and TNF-α-high.