A cross-sectional study was carried out at county, township and village health care facilities in four counties in rural China in order to describe and compare the effects of health financing systems on antibiotic prescribing in outpatient care. A total of 1232 outpatients at the health care facilities was selected by multi-stage random sampling and were interviewed over 2 weeks. The results showed that health financing systems appeared to influence antibiotic prescribing in outpatient care, both in terms of frequency and of the types prescribed. The insured group had lower prescribing of antibiotics at township and village health care facilities, and for respiratory tract infections, but had higher prescribing of newer antibiotics at county and village health care facilities, for respiratory tract and g-i infections. Because there was a high patient compliance rate (94.3%) in this study the prescribing of antibiotics (supply side behavior) reflected the use of antibiotics (demand side behavior) to a great extent. Thus the results imply that antibiotics prescribing and using might be biased by the patient's health financing systems and antibiotic prescribing was the result of the interaction between physicians and patients.