Objective: Using the thesis of magnetic drug targeting system, drug attracted to the tumor site for a period by external magnetic field. Magnetic field distribution was analysis in target site with super paramagnetic material near tumor site. Method: Construct the physical model of nano iron movement. Magnetic field distribution was simulated with the software of ANSYS. Result: Magnetic field near super paramagnetic material have augment significantly, and have show contrast with surrounding tissue. Nano iron can be trapped here in high effi...