The coverage of exclusive breastfeeding in Semarang regency, it is 44.83% on 2015, Lerep Public Health Center is the second of the lowest percentage on it (27.1%). One of the causes is a little milk out. The impact is the presence of infectious diseases and non infections and the impact on infant mortality. Sweet potato leaf is one of the high nutrient leaves and rich in lactogog substances that can increase milk production. The purpose of this research is to prove the influence of boiled sweet potato leaf water on milk production in post partum mother in Work Area of Lerep Health Center of West Ungaran Sub-district, Semarang Regency.This research was conducted at Work Area of Lerep Public Health Center. This research uses experimental design of pre experiment with pre test post test with control group design. The study population was postpartum aged 10-22 days. Method of taking sample data by purposive sampling. All samples will be given an observation sheet that consumes boiled water of sweet potato leaves for 7 days. Analysis with independent and dependent t testThe results showed that there is influence of boiled sweet potato leaves to increase maternal breastfeeding milk production in the Work Area of Lerep Public health centre Sub-district of West Ungaran Semarang Regency. Breastfeeding production based on the estimated volume of breast milk with p-value 0.001.