Abstract: A process of core molding is disclosed, which permits increasing the positioning accuracy of a base core and a bonded core relative to each other and also avoids handling the first molded base core outside the die to preclude such trouble as breakage of the common die. By the process, a complete core is obtained, which comprises a base core and a bonded core positioned in and bonded to the base core. The base core is molded in a molding space which is defined by engaging a die element and a common die with each other. After removing the die element from the common die while leaving the molded base core in the common die, a different die element is engaged with the common die to define a different molding space for molding a bonded core. The bonded core is bonded to the base core as it is molded.