OBJECTIVE:To investigate the distribution of magnetic nanoparticle embedding Paclitaxel in vivo and its curative effect on lung cancer in mice model.METHODS:The magnetic lipsomes containing Paclitaxel and the Paclitaxel liposomes were injected into caudal vein of mice,and which were exposed to magnetic field of 0.5T.The concentrations of the two drugs in different organs were determined.The lung cancer model was established in mice and the therapeutic efficacy of the different drugs on tumor was evaluated by comparing the weight of mice before and after administration.RESULTS: In the mice treated with magnetic liposome containing Paclitaxel,the drug concentration in lung which was exposed to magnetic field was significantly higher than that in the others sites,and a steady state concentration was reached quickly in lung after administration,but gradually in other organs.In the mice treated with liposomes containing paclitaxel,a steady state concentration was reached gradually in lung.The tumor control rate was 27.53% in mice treated with magnetic liposome containing Paclitaxel plus magnetic field intervention,significantly higher than in the control group.CONCLUSION: The result shows that magnetic targeting drug delivery is an effective drug delivery system,by which,the drugs can aggregate to the target site in large quantity which may lead to a reduced distribution of drugs in non-target sites.