There has been no mature model for expressing needs and expectations of people within the area of national defense, and it is considered as the most important business in C⁴ISR requirement analysis. In order to cope with this problem, an approach has been put forward in the paper. Firstly, basic concepts were analyzed, the concept of C⁴ISR requirement system was put forward based on concept analysis, and the idea of modeling C⁴ISR requirements was presented. Secondly, elements of C⁴ISR requirements model were studied. Metaclasses in the domain of C⁴ISR requirements and relationships among the metaclasses were distilled and defined. Therefore, C⁴ISR requirements models were designed on purpose to solve C⁴ISR requirement problems. Lastly, the paper provides the process of modeling C⁴ISR requirements based on element analysis. What C⁴ISR requirement models require and how to build the models are clarified. The approach elaborates what the real C⁴ISR requirements are and it can serve as the guideline of modeling C⁴ISR requirements.