THE DRAIN SYSTEM OF THE PBD PUBLIC LAW WHICH HAS THE CORE OF A DOUBLE X FORM

A drain board having an X-shaped core for a plastic board drain method is provided to secure excellent drainage performance by keeping first diagonal members and second diagonal members from a filter at regular intervals, thereby preventing a drainageway from getting clogged. A drain board having an X-shaped core for a PBD(plastic board drain) method comprises a core(20) having a drainageway(25), and a filter(30) covering said core to prevent the inflow of impurities from the ground to the drainageway of the core. The core comprises a plastic board(21) formed by connecting first diagonal members(22) and second diagonal members(23) to cross each other on two sides of the plastic board at an angle of 80~100 degrees to drain off underground interstitial water smoothly and to secure the strength of the plastic board.