An improved partition wall material including a skeletal material, partition boards, and fastening plates. The skeletal material is an elongated extruded structure including a beam at a central portion thereof, and two skeletal projections respectively connected to two ends of the beam, each skeletal projection having two ends that respectively bend outwardly to form respective projection ends. Each projection end is connected to a frame. Each frame includes a frame projection provided with a pair of opposed frame hooks, each of which has a curved portion. The skeletal projection and the frames on both sides thereof defining a frame recess. The partition boards are planar boards including a plurality of locking holes arranged along a longitudinal axis thereof. The fastening plates are integrally bent plates that have one end forming a curved hooking portion corresponding to the frame hook, with the other end forming a straight portion that, together with the hooking portion, is engageable with the corresponding frame hooks. The fastening plate further has a rear hole adapted for passage of a screw therethrough to lock the fastening plate to the corresponding locking hole of the corresponding partition board. The fastening plates and the frames of the skeletal material are thereby inter-connected to enable the partition boards to be secured to the skeletal material.