A burgeoning literature on the informal transactions occurring outside formal institutions has demonstrated the principles of interactions among Chinese people and the important role of “hongbao”（monetary gifts）. There are，however，few studies on the informal transactions between doctors and patients，and on the gift-taking decision of doctors in the field of public healthcare. Drawing on interviews with 30 doctors working at public hospitals in Shanghai and Nanjing，this paper explores why and how doctors decide to take or reject the gift，and how they justify their decisions. Four types of doctor-patient transaction are identified：Quick Fix，Face and Power，Fair Dealing，and “Bao”. The findings show that variation in doctors’ decisions to take the monetary gift from patients lies in doctors’ different definition and interpretation of：（1）their relationship with the patients；（2）the meaning of the exchange；（3）the medium of exchange，such as monetary or non-pecuniary gifts. Different cultures，including authoritative culture，market culture，and family-oriented culture，lead to the variation in interpretation.