A quick open structure for a tool box contains a body including an upper housing, a lower housing, two retaining portions, and two bearing portions; the lower and the lower housings including a first and a second chambers individually, and the first chamber including two grooves respectively and a limiting element extending therefrom, each groove including an opening, the second chamber including a receiving member; wherein the first chamber is provided to receive a locking device and includes a pressing member and an engaging member, the pressing member includes a larger-area press portion and two side straps in response to the grooves, each side strap includes a hole to receive a returning spring, and a first and a second axial rotating portions include a first orifice and a second orifice to insert two shafts respectively, each shaft includes a resilient element, the engaging member includes a fastening block.