The supervisory control and data acquisition (SCADA) system is the core of the critical infrastructures, which becomes the target of cyber criminals due to the endless stream of vulnerability, political purpose and problems of management. In this study, we survey a series of the SCADA systems security issues (including vulnerability and incident response management cycle) and give a closer look at how to provide consistent SCADA security from the integration viewpoint. The security managers or specialists are able to have a comprehensive knowledge about SCADA system security protection recommendations and expect to eliminate security threats via this preliminary study.