Abstract: OBJECTIVE To observe the effects of luteolin on the polarity and inflammatory factor expression in mouse bone marrow derived macrophages, and to preliminarily explore the mechanisms of luteolin regulating the polarity of BMDMs and inhibiting inflammation. METHODS BMDMs derived from C57 BL/6 mice were used as the research objects. 10 ng/ml lipopolases（LPS） and 20 ng/ml interferon were used to stimulate M1 polarization in BMDMs, and 20 ng/ml IL-4 stimulated M2 polarization. The experiment was divided into the control group, LPS+IFN-γ stimulation（M1） group, IL-4 stimulation（M2） group and luteolin treated groups, which were subclassed into the M1+2.5 L group and M1+5 L group by the luteolin dosage used（2.5 μmol/L and 5 μmol/L, respectively） in the condition of LPS+IFN-γ stimulation. The morphology of BMDM was observed by laser confocal microscopy; the levels of BMDM differentiation, CD11 c and CD206 on the membrane surface were detected by FCM; the mRNA and protein expresion of M1/M2-type inflammatory factors were examined by qPCR and ELISA, respectively; the expression of p-STAT1 and p-STAT6 signal pathways were detected by western-blot. RESULTS The stem cells isolated from mouse bone marrow were successfully differentiated into BMDM, and LPS+IFN-γ induced BMDM M1 polarization, meanwhile IL-4 induced to M2 polarization. After treatment with luteolin, M1-type proinflammatory factors expressed in M1-polarized BMDMs were down-regulated, and M2-type anti-inflammatory factors were up-regulated. The expression of CD11 c on M1 cell membrane surface was down-regulated, and that of CD206 was up-regulated; the level of p-STAT1 protein in the inflammatory pathway decreased whereas p-STAT6 increased. CONCLUSION Luteolin may alter the polarity of BMDM by modulating p-STAT, thereby can regulate the expression of inflammatory mediators.