Abstract: Synthetic assessment(SA) is an important method in C⁴ISR system assessment.The weakness of SA lies in its subjectivity in weighting determination.Aiming at the problem,the paper defines the relations among the indices of C⁴ISR system Effectiveness under system confrontation and constructs a matrix model to describe the relations.The conceptions of reliant weighting(RW) and influence weighting(IW) are raised to depict weighting.Based on a rational assumptions,the paper gives the relational function of RW and IW and proves that the positive RW and IW exist.