Purpose: This study was conducted to discover the related factors of neonatal suckling in the initiation of breastfeeding in primiparous mothers and to provide basic data for promoting nursing intervention strategies to improve the practice of breastfeeding. Method: The subjects of this study were 71 primiparous mothers who had normal vaginal deliveries at one obstetric hospital in P metropolitan city and one delivery center in J city. The collected data was analyzed using the SPSS program. Result: The average IBFAT(Infant Breastfeeding Assessment Tool) score was 9.6$pm$2.3. The general characteristics studied that had a significant influence on neonatal suckling in the initiation of breastfeeding were the place of delivery (ex: Hospital, Postnatal Unit), whether oxytocin was used, no usage of analgesic medication, amount of satisfaction after the first breastfeeding weight of the newborns and the Apgar score at one minute. Conclusions: A higher IBFAT score was related to primiparous mothers who had a hospital delivery, received oxytocin, received maternal labour analgesics, neonatal weight, Apgar score at one minute, and satisfaction after the first breastfeeding.