Studies have consistently showed that informal caregivers have worse health, more medical consultations, anxiety and depression, and lower quality of life than those who do not provide such care. Positive outcomes of psychoeducation interventions have been found, but many of them are relatively long in duration, making them less cost-effective in implementation. The proposed study is a multi-site, three-arm randomized controlled trial of a mindfulness-based intervention for Chinese family caregivers. Effects of the intervention will be compared with those of an evidence-based psychoeducation program and treatment-as-usual. Two hundred forty cross-generational caregivers of frail older adults with moderate to severe levels of frailty will be recruited and randomly assigned to mindfulness-based intervention, psychoeducation, and treatment-as-usual experimental conditions. Program effectiveness will be analyzed on measures of caregiver burden, depression, anxiety, positive caregiving experience, spirituality, family conflict, and the biomarker of heart rate variability. Measures on coping styles, experiential avoidance, and self-efficacy will be explored to see if they mediate the changes to participant improvements in outcomes. Six-month follow-up will be included to investigate the maintenance effects. This study will provide evidence on mindfulness-based interventions on caregivers of frail older adults and expand the existing models of intergenerational caregiving in Chinese culture.