The experiments were performed on BABL/c mice with S-180R adriamycin resistant tumor cells. This animal model was used to analyze the drug accumulation in the S-180R cells by flow cytometer. The drug accumulation presents the pump activity of multidrug resistance (MDR) gene product P-glycoprotein (P-170) in the cell membrane, A weak inhibition was found when moxibustion at Guan-Yan point alone. And a very significant inhibition was observed in the presence of low-dosage of verapamil, but not at high dose. This study may develop a new way to research the mechanism of acupuncture and moxibustion at molecular level, and may be useful to overcome the anticancer drug resistance.