Objectives: To understand the knowledge of breastfeeding and factors that affect the breastfeeding education in Macau. Method: The study was a questionnaire survey of 300 pregnant women who attended a Medical Centre for prenatal check up. Result: On average the respondents scored 48% of the breastfeeding knowledge test. The "Breast-milk's advantage" was the item that gained the highest rate among all items. Following that were the items of "The way to improve the breast-mild secretion", "The characters of breast-milk", "Correct way to breastfeed", "Correct breast care after breast feeding". Most of respondents indicated intention of breastfeeding but only a small proportion had participated breastfeeding seminars. Gestational age, number of birth and educational level were the factors that influence the knowledge of breastfeeding. Conclusion: Inadequacy of breastfeeding knowledge is associated with gestation age, number of birth, educational level, intention of breastfeeding, and experiences of attending breast feeding seminar.