Abstract: By encoding the assembly states with binary variables and establishing the Boolean characteristic functions of assembly operations,a novel symbolic scheme to represent assembly sequences is proposed using ordered binary decision diagrams （OBDD）.In terms of the assembly states and assembly operations corresponding to AND arcs and nodes in an AND/OR graph,the procedures to translate traditional AND/OR graphs to OBDD models are presented. Experimental tests are executed to compare the storage space of AND/OR graph with that of OBDD.The results show that OBDD scheme has the competitive advantages of efficient manipulations and storage spaces for complete and feasible assembly sequences against the AND/OR graphs.