In order to polish complicated-shaped inner surfaces of models, a new polishing method with magnetic congelation liquid was invented, we called this name MAGIC polishing tool. This tool is magnetic fluid at high temperature, can be solidified by cooling. The distribution of abrasives in the liquid can be controlled by magnetic field. Therefore we can make a special polishing tool which has well arranged abrasives inside after cooling. In order to know the fundamental polishing properties of this new polishing tool, brass plate was polished. The polishing tool was pressed and rotated against the brass plate in specified polishing time. After many experiments, it was found that this type of polishing tool provided enough removal rate and surface roughness.