Background: Previous research has shown that care experiences influence the willingness for advance care planning (ACP). Family caregivers have increased contact with medical providers and procedures in the process of caring, and they have also witnessed the disability and suffering of patients. However, few studies have focused on family caregivers to understand their attitudes towards ACP. Objective: The aim of this cross-sectional study was to acknowledge family caregivers’ attitudes towards ACP and the related factors, especially care stress and experiences during the care process. Methods: We interviewed 291 family caregivers, and the demographics of the caregivers and care recipients, the clinical condition of care recipients, and the caregivers’ stress and care experiences were collected via anonymous questionnaires. Multiple logistic regression was performed to determine the factors associated with the attitudes towards ACP. Results: We found that the caregiver having private health insurance (p < 0.001) and a completed DNR (p < 0.001) and the experience of recipients admitted to the ICU (p = 0.019) are associated with caregiver’s positive attitudes towards ACP. The greater the stress of conflict within a family over care decisions, the more participants think that ACP is important (p = 0.011). Conclusion: It is suggested that (1) in a family-centered culture, a public strategy for promoting ACP could be to emphasize the benefits of ACP in reducing family conflicts, and (2) when people make financial plans, they should also be provided with information about ACP to enable them to form a more integral plan for their future.