In this research, the effects of non-uniform magnetic field on the heat transfer of ferrofluid inside a T-junction are investigated. The finite volume method with the SIMPLEC algorithm is applied to simulate the effects of non-uniform magnetic field on the thermal and friction factor of ferrofluid. The ferrofluid inside T-junction is assumed single phase and laminar and constant heat flux is applied on the wall while three wires are chosen as a source of non-uniform magnetic field. This study focused on main effects of magnetic field on the flow feature and temperature distribution in the vicinity of magnetic source. Comprehensive parametric studies are performed to investigate the influence of various factors such as intensity of magnetic field and Reynolds number on the heat transfer. Obtained results show that average heat transfer of ferrofluid rises more than 64% when magnetic field is applied. In addition, the local heat transfer increases more than 200% in vicinity of the first magnetic field.