A ferrofluid is a suspension in which nano-sized magnetic particles are dispersed in colloid solution. Since the ferrofluid is ferromagnetic, the particles do not settle even in a force field such as gravity or magnetic field, and the flow of liquid can be controlled by the magnetic field. When a magnetic field is applied, the magnetic volume force forms a vortex field, which affects the heat transfer characteristics. In this study, heat transfer characteristics of ferrofluids in microchannel were investigated using the commercial code, COMSOL Multiphysics. Numerical results of the local Nusselt number, magnetophoretic force, and temperature distribution were obtained in various configurations of microchannel, and results were graphically depicted with various flow conditions.