Abstract: A path planning system of manipulators in 3-D space is described. After projecting each 3-D obsta-cle twice, the problem of 3-D planning is converted to a 2-D one in projection planes. According to sever-al typical poses of the manipulator, a special search algorithm is designed, which can find a better overallpath using a local search approach. This planning system is realized in Micro VAX Ⅱ in real time.