The Korean government previously established a national blood policy and national blood system based on basic and essential legislation. This achievement was the result of collaborative efforts between the Korean Centers for Disease Control and Prevention, the Korean Society of Blood Transfusion, the Korean Society for Laboratory Medicine, the Laboratory Medicine Foundation, and/or the Korean Association of External Quality Assessment Service. To ensure a safe and effective transfusion, a comprehensive quality assurance (QA) system to assess every process from donor selection to transfusion is mandatory. From a blood safety perspective, selection of appropriate donor blood screening tests for transfusion-transmissible infections (TTI) and the QA program is of great importance. In this article, we review legislation regarding the national blood policy and national blood system as well as the selection logic regarding diagnostic immunologic tests for TTI and quality assurance efforts for TTI of each blood center. (Korean J Blood Transfus 2017;28:225-237)