Abstract: Yudistira Kikhau. 2020. Factors Affecting the Coverage of Ideal K1 Antenatal Services in the Work Area of the Batu Putih Public health center, Batu Putih Sub-District, Timor Tengah Selatan District. Public Health Study Program, Postgraduate Program, Nusa Cendana University. Advisor 1 Dr. dr. Christina Olly Lada, S. Ked., M. Nutrition. Advisor 2. dr. Paula Tibuludji, MPH., Ph.D. The coverage of antenatal services K1 Ideal is the coverage of pregnant women who receive antenatal care for the first time, namely in the first trimester by health workers who have competency according to standards, in a work area at a certain time. It is expected that pregnant women who receive prenatal care as early as possible according to standards can avoid risk occurrence of complications during pregnancy, childbirth and post-partum. The coverage of K1 Ideal services is influenced by predisposing factors, namely age, parity, education, knowledge and attitudes, and enabling factors, namely accessibility and reinforcing factors, namely support from husbands, support from in-laws and socio-culture. The purpose of this study was to analyze the factors that influence the coverage .....................