Background : Specialized and continuous educational program is needed for investigators. A questionnaire survey was performed to examine current status of educational experience, preferred forms and contents for educational program and certification system, prior to development of investigator educational and certification programs. Methods : Developed questionnaires were posted to 738 clinical investigators in October 2005. The questionnaire consisted of questions about demographics, clinical trials experience, educational program experience, and preferred educational and certification program. The analysis included investigators who participated in at least one clinical trial within past 3 years. Results : A total of 122 subjects was responded to the survey (16.5% response rate). Among the total subject 96 (78.7%) had participated in at least one clinical trial within past 3 years and all analyses included only the 96 subjects. Forty three percent had experience to be educated related to clinical trials and over ninety percent had intention to participate in the educational program for investigators. Preferred educational contents for clinical investigators both for basic and advanced course were subject protection and consent, regulation, clinical trial design, statistics and data management, protocol development, randomization, and blinding. Eighty three percent of subjects preferred short-term intensive course with 3 days or less. Investigators participated in any education program once or more agreed to necessity of certification system more than non-participants (p=0.002). University, research center or academic society was preferred for Institution for certification (55.8%). Conclusion : Educational program for investigators specialized by diverse time period and level has tobe developed. Certification for investigators seems to be necessary to improve research capacity and to standardize quality continuously.