Disclosed herein are a semiconductor package substrate and a method for fabricating the same. In the semiconductor package substrate, the circuit layer of the wire bonding pad side differs in thickness from that of the ball pad side to which a half etching process is applied. In addition, a connection through hole is constructed to provide an electrical connection between the plating lead lines on the wire bonding pad side and the ball pad side, thereby preventing electrical disconnection when the plating lead line of the wire bonding pad side is cut.