This multi-method study sought to identify parameters of developmental change and stability of child reaction patterns to interparental conflict in the context of family relations in a sample of 223 6-year-old children and their parents followed over the course of one year. Consistent with the sensitization hypothesis, interparental withdrawal and hostility each consistently and uniquely predicted child distress reactions to conflict even after analytically controlling for parental warmth. Associations were found across multiple domains of child responding (i.e., overt negative affect, subjective negative affect, internal representations) and both concurrent and prospective, autoregressive analyses. Results of the autoregressive path analyses indicated moderate stability in each of the domains of conflict reactivity over the 1-year longitudinal period.