Consensus of intrinsic cognition of the Copyright Act has not been reached in academia. This article holds that the current copyright law has a narrow and broad sense. The narrow sense of the copyright law is the copyright protection law. In the broad sense, copyright law is a collection of institutions of different nature. It is a “three-dimensional structure” with authors' copyright protection as the core value, public use right as the structural value, and common domain as the basic value. The stable operation and ultimate value of copyright law is based on the positioning of different legal subjects in a three-dimensional structure, each paying a price and acquiring rights and freedom of a different nature. The protection of copyright allows authors to contribute their works to ensure that the public has an applicable resource of ideas. The protection of public use right, on the other hand, supports the long-term development of copyright owners' rights and freedom. The interactive consideration among the subjects jointly sustains the institutional goal that a mechanism for the production and reproduction of works tends to stimulate the flourishing of literature and art and cultural industry, and support the operation of a modern state ruled by law.