The rotational plane slicing (RPS) method is proposed for 3-D whole-core neutron transport calculation. This method takes a view of the 3-D structure with a set of vertical planes that are obtained by slicing along the characteristic lines. In a 3-D structure with a simple axial configuration, the sliced planes consist of rectangular cells. Each sliced plane is then analyzed quite easily with a 2-D transport discrete ordinate solver. Several numerical tests are performed and the results indicate that the RPS method reproduces the reference solution with good accuracy.