In this paper, we have proposed the design and implementation for efficient Command Control and Alert(C2A). Information fusion must be done for knowing the state and identification of targets using multi-sensor. The threat priority of targets which are processed and identified by information fusion is calculated by air-defence operation logic. The threat targets are assigned to the valid and effective weapons by nearest neighborhood algorithm. Furthermore, the assignment result allows operators to effectively operate C2A by providing the operators with visualizing symbol color and the assignment pairing color line. We introduce the prototype which is implemented by the proposed design and algorithm.