In order to generate C⁴ISR requirements systemically, systems must be classified in particular. However, the taxonomies of systems are still in their early stage, which is not adaptive to C⁴ISR requirements generation. Therefore, a three-dimensional (3-D) taxonomy, which is based on characters of C⁴ISR requirements and evolutionary rules of weapon materiel, is put forward. In 3-D taxonomy, weapon materiel were classified according to three levels of task illegibility, three levels of structure complexity, and three levels of technological uncertainty. Based on the hypothesis that C⁴ISR requirements generation must be adaptive to the type, it is suggested that C⁴ISR requirements generation comprise three modes, which are reproduction, discovery and creation respectively. They can provide the way to be exact, right and advanced respectively. The relation between the modes of generating C⁴ISR requirements and the types is presented. At last, an example is analyzed to illustrate the pattern. The example shows that the pattern is feasible and that C⁴ISR requirements can be generated systemically.