The Public Security Intelligence Agency is an external organ of the Ministry of Justice established in 1952, when the Subversive Activities Prevention Act came into force, to carry out the comprehensive task of intelligence activity and investigation and to request for control to be imposed on subversive organizations as by the act enacted.

With the implementation of the Act Regarding Control of Organizations Which Committed Indiscriminate Mass Murder, which was enacted in 1999, the Agency got additional duty to conduct intelligence activity and investigation, and to apply for controlling and regulating those organizations which have committed indiscriminate mass murder.

The Public Security Intelligence Agency is comprised of three internal departments, an institute and regional bureaus. The internal departments are the General Affairs Department, the First Intelligence Department and the Second Intelligence Department. The institute is called the Public Security Intelligence Agency Training Institute. The regional bureaus consist of eight Public Security Intelligence Bureaus and 14 Public Security Intelligence Offices located nationwide.