Abstract: Assembly is a kind of dextrous,complex and intelligent controlled operation.Robotized assembly needsrule and decision supports.The goal of assembly,main relations and movements of assembly are presented inthis paper.Some basic rules about disassembly and assembly of component parts are given.Constraint repre-sentation and a decision algorithm on linear disassembly are discussed.The algorithm was verified with a twodimension problem,the block diagram and the source program are also presented.