This study investigated professional values on which the practices and the perceptions of professions were based, then identified common professional values and different ones. The codes of ethics by professional organizations of libraries, archives, or museums in the U.S., Canada, the U.K. and Australia were selected for the analysis. Predicated on the literature review, common professional values were derived from the existing studies. While conducting the analysis, 13 values were identified and finalized. As a result, it was found that common professional values included access, privacy, stewardship, professional conduct and professional responsibilities to the society. Intellectual freedom in the library area, records as an evidence in the archive area, and research and interpretation in the museum area are those emphasized and unique in each area.