[en] Last decade, nuclear I and C industry in Korea has endeavored to apply the digital technology to nuclear plants. The Korea Nuclear I and C R and D Center is developing a safety-grade Programmable Logic Controller (PLC) and a Distributed Control System (DCS), and designing in parallel the I and C systems such as plant protection system, plant control and component control systems, with the purpose of supplying them to the nuclear plants in our country. In addition, the design technology for monitoring and operator aid system is included to support the control room design in the future. These are integrated into the I and C system design for completing a localized I and C system package. This report proposes a general design specification for the DCS. The DCS is considered as a platform equipment for the control system that is relatively important for the design of an integrated I and C system. This report is expected to provide vital input for future work on the integrated I and C system design and a guide for the selection of control system equipment