With constantly increasing accesses of distributed generators and diversity load development such as electric vehicles, the operational control of distribution network is facing a huge challenge. In order to make full use of active distribution network and meet the development requirement of smart grid, this paper proposes a coordinated control system in active distribution network. The paper elaborates the general architectural design, software architectural design, and functional designs including of characteristic analysis, situation awareness and coordinated control. Through the coordinated interaction and control of source-load-storage being realized, the potential of controllable resources in distribution network is fully exploited, distributed generator optimizes its power generation absorption and diversity load improves its ability of participating in electric network load adjustment basing on active distribution network in safe and reliable operation. The coordinated control system designed and developed based on this paper has been applied in Changzhou distribution network.