Although the sensitization hypothesis posits that heightened reactivity to interparental conflict is linked to adolescent psychopathology, limited studies tested whether sensitization would emerge in parent-adolescent conflict and across ethnicity or culture. This study revisits the sensitization hypothesis by examining adolescent emotional reactivity to interparental and parent-adolescent conflicts on a daily timescale. The sample included 163 adolescents (55% girls; M
age = 12.79) and their parents (78% females; M
age = 45.46) who completed a 10-day reports in Taiwan. Multilevel modeling results showed that, instead of interparental conflict, adolescents with greater histories of parent-adolescent conflict exhibited higher emotional reactivity when parent-adolescent conflict was higher. The findings underscore the importance of parent-adolescent conflict in evaluating adolescent developmental risk.