A tool box includes a main body, a mounting seat pivotally mounted on the main body for mounting a hand tool, a positioning member movably mounted in the main body and releasably locked onto the mounting seat, and at least one tool holder pivotally mounted on the main body for mounting a plurality of tool heads. The main body includes an upper shell and a lower shell. The upper shell has a mounting hole for mounting a control knob. The tool holder has a mounting sleeve for mounting a push button. Thus, the user only needs to press the control knob and the push button to pivot the mounting seat and the tool holder respectively so that the mounting seat and the tool holder can be opened easily and quickly.