An edge-coloring of a graph is an assignment of colors on edges so that no two adjacent edges have the same color. In particular, it is a 3-edge-coloring if it uses at most three colors. In a 3-edge-coloring, if we choose a bicolored cycle and swap the colors on the cycle, we obtain another 3-edge-coloring. This operation is introduced by Kempe for the attempt to solve 4 Color Problem, and is still useful method for several related problems. In this talk, we discuss the reconfiguration problem of 3-edge-colorings in cubic graphs under the operation.