A mounting structure for connecting detachably a saw blade guard to a worktable of a bench saw includes a first connector at the worktable, a second connector at the saw blade guard, and a fastening member for fastening the second connector to the first connector. The first connector has a block member provided with a screw hole. The second connector has a connecting block provided with a through hole and a conical hole, and a cone fitted into the conical hole and having a through hole and a socket fitted onto the block member. The fastening member has a head stopped at one end of the connecting block, and a threaded shank inserted through the through hole of the connecting block and the through hole of the cone and threaded into the screw hole of the block member to lock the second connector to the first connector.