Objective: The present study aimed to identify the most important protective factors predicting caregivers' depressive symptoms among factors of caregivers' dispositional mindfulness, self‐compassion, compassion from others, and patients' dispositional mindfulness and their moderator effects on the relationship between caregiving stress and depressive symptoms. Methods: A total of 72 lung cancer outpatients and their family caregivers participated in this study. Family caregivers completed the Kingston Caregiver Stress Scale, Beck Depression Inventory‐II (BDI‐II), Five Facet Mindfulness Questionnaire (FFMQ), Self‐Compassion Scale, and Compassion from Others Scale. Patients completed the EORTC Quality of Life Questionnaire Core 30 (EORTC QLQ‐C30), BDI‐II, and FFMQ. Results: After controlling for patients' factors (treatment status, symptom distress, and depressive symptoms) and caregivers' health status, caregivers' stress and dispositional mindfulness, the domain of mindful awareness, and self‐compassionate action were significantly associated with their depressive symptoms. Further analysis indicated that mindful awareness or self‐compassionate action could buffer the effect of caregiving stress on depressive symptoms. When the two moderators, mindful awareness and self‐compassionate action, were tested simultaneously, only self‐compassionate action remained as a significant moderating effect. Conclusions: Caregivers' mindful awareness and self‐compassionate action were protective factors, which mitigate the impact of caregiving stress on their depressive symptoms. Therefore, the future supportive program aims at training the competencies of self‐compassionate action with mindful awareness, which may enhance caregivers' coping resources