OBJECTIVES: To investigate outpatients' knowledge, attitude and awareness on medication and analyze the influential factors. METHODS: A total of 711 outpatients who consented to participate the survey were recruited from 306 Hospital of PLA in Beijing between 2009-2012. The self- administered questionnaire was composed of XX questions. Multiple linear regressions were run to explore the influential factors. Data were analyzed using STATA v11.0. RESULTS: The outpatients investigated showed a poor cognition on rational drug use. 84.8% of the patients would stop taking drugs by themselves. 60.1% of the patients were aware of adverse drug reactions. Age, urban-rural difference, knowledge of medication, and health status have different degrees of influence on the medication behavior and medication willingness of patients, while family income and health insurance have little influence. Information provided by the patients was compared with the prescriptions. CONCLUSIONS: These results suggest that outpatients in China had much misunderstanding about drug use. Patients’ education regarding rational drug use is an important issue and deserves urgent improvement. KEY WORDS: Outpatients; Cognition; Determinants; Rational use of drug; Self-medication