The Children's Perception of Support Inventory (CPSI) which assesses the extent to which children perceive their families and peer networks as understanding, responsive, and supportive is described. This measure was constructed (1) to differentiate children on family and peer-support scales and to demonstrate the relationship between the perception of support and help-seeking behavior, and (2) to investigate whether a child's perception of support from family and peers changes with age. The means for selecting the CPSI items is detailed: three independent measures were reviewed, five judges determined how appropriately each of 100 items characterized children's help-seeking behavior following a crisis, and the experts' judgments were used to compile the CPSI. The 45 items selected measure the extent to which children perceive their families as helpful and supportive, the degree to which friends are perceived to give support, and the extent to which children believe external or internal factors control their lives. Directions for scoring the measure are provided, and psychometric procedures used to establish reliability and validity are described. Norms for age groups, as well as a guide for interpreting results, are given. (Author/DB)