A floorboard assembly includes floor boards and fasteners. Each floor board includes a rectangular body including a coupling tongue and a coupling groove at two opposite sides, a first pressure block and a second pressure block respectively disposed at a bottom side relative to the coupling tongue and the coupling groove, a recessed portion disposed in an outer upper side of the first pressure block and a step respectively disposed in an outer upper side of the second pressure block. Each fastener includes a base panel having a front baffle and a rear baffle at two opposite sides, a partition rib spaced between the front and rear baffles, and a hooked portion curved from the top of the partition rib.