Hypoxia, a decrease in oxygen tension occurring in pathological tissues, has a profound effect on macrophage functions. In this study, we have investigated cellular and molecular responses of murine macrophage-like RAW264.7 cells to low oxygen tension. Our study revealed that hypoxia induced RAW264.7 cells apoptosis and cell cycle arrest at G0/G1 phase. The result of Western blotting showed that the expression of apoptosis related signaling molecules, such as AKT and JNK was activated under hypoxia. The result of electrophoretic mobility shift assay showed that the DNA binding activity of nuclear factor kappa B (NF-kappaB) was also increased by hypoxic stimulation. Furthermore, gene expression profiles of RAW264.7 macrophages induced by hypoxia showed that hypoxia treatment may alter expression of genes related to apoptosis, survival, cell cycle, metabolism and structural matrix.