Custody during investigation has been one of the significant issues of social concern. Its application and practice represent an important part of the image of Justice system. Many of the court detention cases have created huge gaps in conception between people and justice practitioners. This paper will begin to discuss the meaning of custody, its purpose and the relationship among its functions. The paper will try to further explore their dynamic interrelationship and connectivity, and also to identify the specifics of their mutual acceptance or conflict. Specifically, with respect to dealing with the differences between the previsions of law and actual practice in real life, this paper will address other essential elements such as human rights, social order, individual's freedom and public demands. The discussions will try to use a broad enough view to seek for either a possible bridge or a range within which people and justice practitioners can create better mutual acceptance with the defined reasonable tolerance to further enhance social harmony.