Electro-Pneumatic sequencial circuit(EPSC), which controlled by PLC takes as important role in all kinds of production lines. An easy method to design this kind of EPSC is put forward in this paper. Based on this method, a CAD software for EPSC, named PneuCAD that allows users to design, simulate and animate circuits consisting of electro-pneumatic sequencial systems. PneuCAD is the ideal CAD and simulation tool for teachers, students and engineers who specialized in pneumatics.