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Objective To investigate the mechanism of luteolin's (Lut) reversal effect on multidrug resistance of chronic myeloid leukemia K562/ADR cells. Methods CCK-8 assay was used to detect drug resistance in K562 and K562/ADR cells 24 hours after treatment with different doses of adriamycin (ADR). CCK-8 assay was used to assess the cytotoxicity and sensitizing effect of Lut on ADR after K562/ADR cells were treated with Lut alone or in combination with ADR for 24 hours. K562/ADR cells in logarithmic growth phase were separated into three group: 0 µmol/L Lut, 2 µmol/L and 4 µmol/L Lut groups. ADR accumulation in cells was measured using flow cytometry. Nuclear factor erythroid-2-related factor 2 (Nrf2), multidrug resistance associated protein 1 (MRP1), P-glycoprotein (P-gp) and glutathione-S-transferase-PI (GST-pi) mRNA and protein expressions were identified using RT-PCR and Western blot assay. Glutathione (GSH) kit was used to detect intracellular GSH content. Results Compared with K562 cells, K562/ADR cell line was significantly resistant to ADR, and the drug resistance was 53.69 times. K562/ADR cell proliferation was decreased to variable degrees by different doses of Lut when compared to the 0 µmol/L Lut group (P＜0.05). The proliferation inhibition rates of K562/ADR cells treated with 2 and 4 µmol/L Lut were less than 10%, indicating that the concentration of Lut was non-toxic. Compared with the 0 µmol/L Lut group, the 2 µmol/L Lut group and the 4 µmol/L Lut group showed significantly increased ADR growth inhibition rate on K562/ADR and increased accumulation of ADR in cells, improved the reversal resistance fold, and decreased GSH content in cells. MRP1, P-gp, GST-pi and Nrf2 mRNA and protein expression were reduced in cells (P＜ 0.05). The effect of 4 mol/L Lut was greater than that of 2 mol/L Lut. Conclusion Lut may decrease K562/ADR cell proliferation and reverse ADR medication resistance. The mechanism could be connected to the downregulation of Nrf2, MRP1, P-gp and GST-pi expression, which leads to an increase in ADR accumulation in K562/ADR cells. [ABSTRACT FROM AUTHOR]