Abstract: Plug joint system and method of use are described for collapsible furniture. This new type of furniture joinery results in furniture which can quickly and easily be assembled, disassembled, transported, stored and reassembled. The joint comprises a tapered plug, a square hole at the top end of one furniture part for receiving the plug, and another furniture part with an opening through which the first furniture part is inserted. Each corner of the square hole has a vertical relief cut, allowing the four sides to expand outward when the plug is driven into the hole, securely fixing the two furniture parts together. The plug can easily be dislodged from the square hole by applying pressure from the bottom of the hole.