Correlation between Breastfeeding Frequency and Onset of Lactation among Multipara Mother in East Jakarta. Delayed onset of lactation is one of risk factor of unsuccessful effective breastfeeding. Mother who get delayed onset of lactation are in a risk of early breastfeeding cessation. Delayed onset of lactation and unsuccessfull effective breastfeeding can be happen to multipara mother, so that some attention about onset of lactation need to paid to them. The aim of this study was to identify correlation between breastfeeding frequency and onset of lactation among multipara mother. The research design of this study was analityc descriptive with cohort prospective approach. The subjects of this study were 148 pospartum multipara mother in East Jakarta, selected by consecutive sampling technique. The Spearman correlation test and linier regression are used in the analysis of this study. The result showed significant correlations between breastfeeding frequency, stress level and onset of lactation p 0,001 . One less frequent mother breastfeed her baby, the longer timing of the onset of lactation at about 0,237 day. The higher mother rsquo s level of stress, timing of the onset lactation would be longer 0,135 day. Finding of this study give recommendation for the health care worker to encourage mother to breastfeed her baby frequently and recognise the symptom of stress at postpartum mother in their early phase of breastfeeding. Some interventions to reduce mother rsquo s level of stress need to be established to help the onset of lactation comes.