Abstract: An automatic routing program system for the wiring of multilayer printed circuit boards is presented,The system employs the iterative placement algorithm and improved Lee's routing algorithm.As the list of wiring connection of a PCB is given,the wire routing can automatically be printed out and a tape,which can be used to drive devices of automatic photographic plotting and automativ punching of PCB,is obtained at the same time.This automatic routing program system has been applied in the manufacturing of 122 multilayer PCBs More than 96% wire connection has successfully been laid.