Hybrid power transmission lines, which comprise a combination of overhead line and underground cable sections, are recently being developed by power utilities due to some noticeable reasons. Since, there are large differences between parameters of these sections, these kinds of lines are nonhomogeneous. Hence, conventional protection and fault location methods are inapplicable to hybrid lines. In this regard, we introduce a transfer matrix-based unit protection approach to obtain a new criterion for fault detection, classification and faulted section identification on a two-section hybrid line. Indeed, calculated voltages of the junction point of the overhead line and underground cable sections from both ends play roles as key factors of the proposed method. In this paper, MATLAB Simulink is utilized to implement computer simulation studies. Simulation results confirm security, dependability and efficiency of the proposed approach.