Abstract: To study the rate of hepatoma cell apoptosis and the reduction in tumor size after administering paclitaxel albumin magnetic nanoparticles ( MAG-TAX-NP ) in combination with iodized oil embolization. Methods: The chemical co-precipitation method was used to prepare the magnetic fluid. Cell apoptosis was determined by flow cytometry. Morphological changes in HepG2 liver cancer cells were observed using electron microscopy following exposure to magnetic microspheres. The emulsification-ultrasonic-solidification heat method was used to prepare the paclitaxel magnetic nanoparticles. Thirty liver tumor-bearing rats were randomly divided into 5 groups. The rats in the 4 treatment groups were injected with 0.2 mL of iodized oil, taxol iodized oil, iodized oil nanometer ferrofluid, or paclitaxel albumin iodized oil magnetic nanoparticles via the hepatic artery, respectively, while a control group was left untreated. The dosage of paclitaxel was 5 mg/kg bodyweight, and magnetic fields were applied over the liver tumor area. Rats from all 4 treatment groups were sacrificed 14 days later and the liver tumors were weighed and compared to the control group to calculate the inhibition ratio. Results: The induction of HepG2 cell apoptosis by magnetic fluid was confirmed by electron microscopy. The formation of apoptotic bodies and cell lysis after phagocytosis of HepG2 cells was also observed. In the liver tumor-bearing rats, the inhibition ratios were 43.2% ( iodized oil ), 51% ( taxol iodized oil ), 57.4% ( oil nanometer ferrofluid ), and 87.4% ( paclitaxel albumin iodized oil magnetic nanoparticles ). Conclusion: Magnetic microspheres can induce the apoptosis of HepG2 cells. Paclitaxel albumin iodized oil magnetic nanoparticles mediated embolization of the rat hepatoma and inhibited tumor growth more strongly than iodized oil embolization alone or paclitaxel iodized oil embolization. Further advances in the use of these magnetic fluids may lead to a new method of cancer treatment. Paclitaxel albumin magnetic nanoparticle may be a highly effective formulation of paclitaxel for treating liver cancer.