OBJECTIVE To study the regulation of luteolin on spleen cells and sarcoma S180 cells in normal ICR mice. METHODS Spleen cells and S180 cells were incubated with different concentrations of luteolin (50, 100, 200, and 400 μmol/L). The effect of luteolin on spleen cells and sarcoma S180 cells was determined by MTT assay. The apoptosis was detected using propidium iodide staining flow cytometry. Intracellular reactive oxygen species (ROS) was determined by flow cytometric analysis. Activities of free radicals scavenging were determined by hydroxyl radical and DPPH tests. RESULTS Compared with the solvent control group, 200 and 400 μmol/L luteolin increased the spleen cells viability (P < 0.05). Luteolin at 100, 200, and 400 μmol/L decreased activities of S180 cells (P < 0.01). The proportion of sub-G1 phase spleen cells was reduced after treated with 200 and 400 μmol/L luteolin (P < 0.05). The proportion of sub-G1 phase S180 cells was elevated after treated with 200 and 400 μmol/L luteolin (P < 0.05). Compared with the solvent control group, levels of intracellular ROS in spleen cells of ICR mice all increased; levels of intracellular ROS in S180 cells all decreased after treated with 50, 100, 200, and 400 μmol/L luteolin (P < 0.05). Luteolin scavenged hydroxyl radical and DPPH in a dose dependent manner. CONCLUSION Luteolin had bilateral regulation on viability and apoptosis of spleen cells and S180 cells (promoting the viability of spleen cells, inhibiting apoptosis of spleen cells, inhibiting the viability of S180 cells, and promoting apoptosis of S180 cells), which was worth further study and exploration.