Abstract: The concept of tool positioning constraints and tool manipulation technique in virtual disassembly environment are discussed.The manipulation procedure of disassembly with tool is studied and the tool positioning constraints of common tools are analyzed.The accurate positioning of tool in virtual environment is investigated as well.An assembly of Bel-l roller is taken as an example in which fasteners are disassembled using screwdriver and wrench in immersive virtual environment based on the tool positioning constraints.