Provided is an intramedullary (IM) rod for bone fixation. The IM rod is configured to be placed in an intramedullary cavity of a center portion of a part of a fractured bone which is required to be fixed to another part of the fractured bone, and lengthily extends in a direction of the part of the fractured bone, wherein the IM rod includes a plurality of guide holes configured to guide fasteners which are inserted through the part of the fractured bone and fastened to the other part of the fractured bone, and the plurality of guide holes include a main hole and a pair of sub-holes provided at positions forming vertices of a triangle together with the main hole.