The present disclosure illustrates to a fiber module rack system in which a rack includes receiving spaces which each is formed by two frame plates of a base panel. Shell bodies of fiber optic cassettes are mounted in the receiving spaces, and a fiber module is disposed at a front part of the shell body, and a resilient locking member is disposed between the sliding track and at least one side of the shell body, so that the user can quickly and easily dismount the fiber optic cassettes from the rack without using tool.