Abstract: Objective:To investigate the effects of Chinese herbs of strengthening and invigorating genuine qi on multi -drug resistant lung cancer through regulating mitochondria related molecules. Methods:The multidrug resistant lung cancer cell line SW1573/2R120 was treated with YQFZ and Doxorubicin (Dox), in vitro. Flow cytometry was used to detect apopto-sis and MRP expression. Cellular ultrastructure was observed with atomic force microscopy. Mitochondrial oxidative phos-phorylation was tested using a biological oxygen monitor. Mitochondrial membrane potential, ROS and intracellular Ca2 + concentration were detected using laser scanning confocal microscopy. Caspase- 3 and Caspase-8 activity were detected by enzyme-linked immunosorbent assay (ELISA). Results: Obviously enhanced Dox apoptotic effect was observed. In the Chinese herbs/Dox group, distinct early apoptotic ultrastructural changes were observed. Chinese herbs increased the Dox induced injuries to mitochondrial oxidative phosphorylation. The values of S 3, RCI and ADP/O were reduced by 57.1% , 53.8% and 48.3%, respectively, in the Chinese herbs/Dox group. This group also showed reduced MRP expression, mito-chondrial membrane potential, ROS and intracellular Ca2 + concentration and increased Caspase-3 and Caspase-8 activity by1.64folds and 1.13folds. Conclusion:Chinese herbs of strengthening and invigorating genuine qi can obviously inter-fere with the drug resistance of lung cancer cells and have a synergistic effect with Dox on promoting apoptosis through regulating mitochondrial molecules.