Situational awareness in the context of cyber security has been well recognized. In a time cyber-attacks getting increasingly sophisticated and making potentially disruptive impacts, it becomes apparent that a holistic approach is fundamentally needed to handling security data effectively. Cyber Security Situational Awareness (CSSA) emerges timely. In this paper, after revisiting the concept of CSSA, we have aligned the process of CSSA with security data lifecycle and analyzed the requirements of CSSA. Then, we have put forward a multi-level analysis framework for CSSA.