On behalf of Korean Society of Obstetrics and Gynecology, I am extremely honored to welcome numerous celebrated professors and promising young colleagues to share different experiences at the 20th Seoul International Symposium. Every year the scientific program consists of diverse presentations by distinguished speakers, presenting on updated topics in the clinical fields and basic research studies to enhance further medical development. Various subjects in Obstetrics and Gynecology will be discussed and debated on issues in maternal-fetal medicine, gynecologic oncology, reproductive endocrinology and general gynecology. New insights into maternal-placental-fetal communication interface, preeclampsia treatment, updates on bone density features in the puerperal period, the role of endometrial stem cells, discussion about gasless laparoscopic myomectomy without morcellation are only a few of the hot items in our programme. The purpose of this symposium is to provide great opportunities to share different opinions on specific subjects and current issues. It will also be an opportunity to our younger colleagues to participate in these high-leveled discussions and expect chances to receive answers to open questions. Thus, your participation will be the crucial part to form a fruitful platform in order to share our knowledge and build a broad base of therapy features for our patients. We welcome you and hope you enjoy our sessions and your stay in Korea.