Conceptual model for describing military requirements of C⁴ISR plays an important role for modeling C⁴ISR requirements. Based on the analysis of the model for C² process, a conceptual model for C⁴ISR military requirements description is put forward. On the whole, the conceptual model comprises object, subject and modeling. At the same time, the common concepts and terminologies, which are often used to describe C⁴ISR requirements, are defined. With the help of the conceptual model for describing C⁴ISR military requirements, relations among these common concepts and terminologies are explained and clarified. Therefore, constraints and fundamentals for describing C⁴ISR military requirements are presented. Finally, an example about anti-air system is presented, which shows that the conceptual model is highly feasible and promising.