A brake disc assembly includes a hub member, a rotor member and a plurality of air guide plates. The hub member is provided to be connected to a wheel hub. The rotor member includes an annular portion and a plurality of support limbs that protrude radially inward from an inner peripheral face of the annular portion and are joined to a periphery of the hub member by bolts. The air guide plates are disposed in a circumferential direction about a central axis of the hub member. Each of the air guide plates substantially interposed in a gap between adjacent two of the support limbs of the rotor member.