The incidence of gastrointestinal and respiratory infections is one of the causes of the high infant mortality rate in Indonesia, which is caused by early complementary feeding (MP-ASI). This study aims to determine the frequency distribution of mother's knowledge, mother's attitudes, family support, mother's occupation by giving early complementary breastfeeding to infants 0-6 months at the Cahaya Clinic in 2020. This type of research is analytic (cross sectional) to determine the calculation of causal and consequential factors carried out simultaneously to determine the factors associated with early complementary breastfeeding at the Light Clinic in 2020. using primary and secondary data. The data were obtained by means of measuring observations and guided interviews using a checklist sheet with a total sample of 34 people, the sampling technique was total sampling, with univariate and bivariate data analysis. The results obtained a significant value, namely the ρ-value of the knowledge variable = 0.033 <0.05, attitude = 0.002 <0.05, family support = 0.011 <0.05, work = 0.024 <0.05, which means that there is a relationship between knowledge, attitudes, family support and work with the provision of MP -ASI for infants 0-6 months at Klinik Cahaya Medan in December - July 2020.