Abstract: Provided are functional socks including cushion members provided at center areas of bottom surfaces of a pair of left and right socks to maintain recessed areas of soles, and shock absorbing units provided at the cushion members and deformed by the weight transmitted to the recessed areas of the soles to attach the soles to shoes. The shock absorbing unit is formed at the bottom surface of the cushion member, and is selectively constituted by one of a honeycomb structure partitioned by a plurality of support ribs, a plurality of holes disposed parallel to a longitudinal direction of the sole, and a plurality of grooves disposed perpendicular to a longitudinal direction of the sole. Side coating sections prevent the soles from being pushed outward, front and rear coating sections prevent slippage, and top coating sections attach toes and tops to shoes.