This study aims to compare the efficacy of group-based CBT-I and CBT-A in reducing the severity of insomnia and anxiety symptoms, as well as other depressive symptoms and daytime functioning (e.g. sleepiness, fatigue) in adolescents with comorbid insomnia and anxiety, when compared with the waiting-list control. Additionally, this study investigates the potential change of general and sleep-related attentional bias after the group-based CBT-I and CBT-A treatment.