A packaging substrate includes a core board having a first surface and an opposite second surface; at least a conic through hole formed in the core board and penetrating the first and second surfaces; a plurality of conductive paths formed on a wall of the conic through hole, free from being electrically connected to one another in the conic through hole; and a plurality of first circuits and second circuits disposed on the first and second surfaces of the core board, respectively, and being in contact with peripheries of two ends of the conic through hole, wherein each of the first circuits is electrically connected through each of the conductive paths to each of the second circuits. Compared to the prior art, the packaging substrate has a reduced number of through holes or vias and an increased overall layout density.