The intense need for breast milk by babies makes mothers have to be extra in the initiation of breastfeeding their babies, especially for their first life. However, many mothers are unable to give breast milk because breast milk is not smooth and various obstacles that can be caused by many factors. Given the importance of breastfeeding, it is necessary to intervene to promote breastfeeding, one of which is back massage with oxytocin massage. This study aims to determine the effect of oxytocin massage on the smoothness of breast milk in breastfeeding mothers at the Blooto Health Center, Mojokerto City. The research design used The One Group Pre Test-Post Test Design. The population in this study were all postpartum mothers who gave breast milk at the Blooto Health Center, Mojokerto City on March 24 - April 30, 2021 as many as 28 respondents until a sample was obtained, namely breastfeeding mothers on the first day who gave birth normally in the working area of the Puskesmas Blooto Health Center which amounted to 28 taken. using a non-probability sampling technique. The independent variable in this study was Oxytocin Massage and the dependent variable was the smoothness of breast milk. Data was taken using a questionnaire. Data processing was carried out with SPSS Statistics 16.0 software and tested using the Wilcoxon Signed Rank Test statistical test. The results showed that oxytocin massage was effective in increasing the smoothness of breast milk in breastfeeding mothers in the working area of the Blooto Health Center, Mojokerto City, because Oxytocin massage was able to increase comfort and milk production for postpartum mothers. The smooth release of breast milk is due to the increased comfort in the mother which will automatically stimulate the release of this oxytocin hormone. And the effect of the oxytocin hormone stimulates the smooth flow of breast milk in nursing mothers so that milk automatically runs smoothly.