Objective To study the inhibitory mechanism of oral adriamycin magnetic fluid combined with extracorporeal magnetic field therapy for implanted gastric tumor in rats.Methods Rat models of implanted gastric tumor were duplicated with Walker-256 tumor cells and divided into three groups: targeting group, non-targeting group and control group. The therapeutic effects including general condition of rats,rate of tumor growth,rats survival duration,histopathology of implanted tumor were evaluated and compared among three groups.Results Compared with the control group, the growth of implanted gastric tumor of rats in targeting group was obviously slower.The inhibitory rate of tumor weight and volume was 78.08% and 82.52% respectively (χ2=27.96,P<0.01). The rats survival duration was markedly prolonged, the prolonged rate was 286.38%(χ2=7.54,P<0.01).Remarkable histopathologic change in the implanted gastric tumor was found.Conclusions The study shows that the targeting therapy of the adriamycin magetic fluid combined with extracorporeal magnetic field has significant inhibitory effects for implanted gastric tumor in rats. It provides an experimental evidence for further clinical application too.