18 Background: Advance directives (ADs) are a sensitive issue among traditional Chinese people, who usually refrain from mentioning this topic until it is imperative. Medical decisions for cancer patients are made by their families, which might violate patients’ personal will. This study was aimed to examine the acceptance of ADs among Chinese cancer patients and their families and patient participation in this procedure. Finally, to analyze the moral risk involved. Methods: Participants included 412 adult cancer patients from 9 leading hospitals across China. An AD was introduced to the main decision makers for each patient; if they wished to sign it, the AD would be systematically discussed. A questionnaire was given to the oncologists in charge of each patient to evaluate the interaction between families and patients, patients’ awareness of their disease, and participation in an AD. Results: A total of 246 patients and their family members rejected systematic discussion of AD, the majority (95.5%) of whom were under anti-cancer treatment. An additional 166 patients or their families accepted the concept of an AD and signed an AD to give up invasive treatment. This decision was make shortly after termination of anti-cancer therapy. Correlational analysis revealed that patients living in villages and who were subordinate members in their families tended to accept an AD. Of these, only 24 patients participated in the decision making. Correlational analysis revealed that patients with a better financial situation, living in cities, and superordinate status in their families tended to participate in the AD discussion, as well as those who usually made medical decisions themselves. Nearly all the patients deciding their own AD knew their entire situation, including diagnosis and prognosis. For 101 patients, anti-cancer therapy was ended prematurely, with as many as 37 patients not told about their potential loss of health interests. Conclusions: ADs were widely accepted among Chinese cancer patients when anti-cancer therapy was terminated. Most cancer patients were excluded from the discussion of an AD. Thus, AD could be formally introduced to the family of Chinese cancer patients after termination of anti-cancer therapy.