The present invention discloses a rack mountable to a computer cabinet without using a tool, and the rack includes a slide module and a latch element, and the slide module includes an adjusting element and a latch element. The latch element includes at least one hook extended horizontally and at least one protruding pillar proximate to the hook. During installation, the hook is latched into a positioning hole of the computer cabinet, and a turning member of the latch element is turned to extend the protruding pillar deep into the positioning hole, so that the hook will not be separated from the positioning hole when the protruding pillar is pressed. On the other hand, users simply need to return the turning member to its original position to separate the protruding pillar from the positioning hole, so as to disassemble the rack.