An integrated circuit package has a printed circuit board, a die mounted on the printed circuit board, and a heat spreader attached to the printed circuit board to cover the die and contact with the backside of the die. The heat spreader is formed by a piece body and a plurality of supporting leads extended downward from the periphery of the piece body. The supporting leads of the heat spreader are attached to the printed circuit board by surface mounting technology. The piece body of the heat spreader abuts on the backside of the die so that heat from the die can be conducted both upward to the outer environment and downward to the printed circuit board through the heat spreader, thereby enhancing the heat dissipation efficiency.