In design of Client Server System (CSS), rapid progress of technology prevents an individual System Engineer (SE) from utilizing effective cases. For various combinations of hardware and software and difficult requierment analysis, it is difficult for SE to acquire CSS design technique and it is useful to support CSS design with computer. We propose a CSS configuration design support system which consists of following four parts, a requirement analysis part, a design suggestion part, a design analysis-explanation part and a learning part. Especially, the design analysis-explanation part makes educational support to SE for CSS design, because the part explains how suggested CSS satisfies requirements. This explanation is written in natural language as a scenario which shows how the suggested CSS is produced. The scenario is generated based on structural models which show the process of requirement analysis and design assumptions. To generate concise scenarios, effective information is selected using the models.