On behalf of Korean Society of Obstetrics and Gynecology, I would like to welcome all overseas clinicians and scientists to the 23rd Seoul International Symposium in Seoul, Korea from September 29, 2018. This year, the scientific program consists of very special three sessions. The first session has been prepared with the Asia and Oceania Federation of Obstetrics and Gynaecology. Prof. Haywood L. Brown, the past president of American College of Obstetricians and Gynecologists, will be a speaker with the topic of pregnancy complications and long term women’s health. In the same session, Prof. Rohana Haththotuwa, the secretary general of AOFOG, will give a speech on the complications of embryo transfer and ovum retrieval in ART. Prof. Young-Tak Kim, AOFOG Oncology Committee Chair, will give a talk on the fertility sparing surgery for gynecologic cancers. The second session is composed of the up-to-date topics on gynecologic oncology and general gynecology. Lastly, the third session consists of both basic and clinical fields on the maternal-fetal medicine and reproductive endocrinology. All the presentations will be given by the distinguished speakers from the different countries as new Honorary members of KSOG. I believe that the Seoul International Symposium will provide a platform to share recent information with active discussion and to enhance our academic competence. Moreover, I am confident that this symposium will make all the speakers and other participants including young doctors experience better acquaintance and closer relationships with each other. Welcome again all the participants from every country. I hope every participant enjoys the scientific festival and has a wonderful memory in Seoul, Korea.