123 decision diagram is a very effective PTL synthesis tool based on binary decision diagram. It realizes a logic function using NMOS pass transistors with CMOS restoring buffers. In this paper the 123 decision diagram is applied to realize CMOS pass transistor logic circuits without restoring buffers. Cell circuits for the 4 bit adder is realized with the CMOS pass transistors using the 123 decision diagram and 4 bit adder is completed by combining the cells.