The contents of copper, iron, zinc, manganese and chronium in human milk, taking from different lactation period (1-90 days), and cow's milk -were determined by atomic absorption spectrophotometry.We found that the concentrations of copper, iron, zinc and manganese in human milk declined during tie course of lactation, and that of copper, iron, zinc and chroninm in human milk were higher than that in cow's milk. When comparison of the essential trace elements intake of breast feeding and cow's milk feeding infant with the values recommended, the breast feeding was more optional than cow's milk feeding from nutritional point of view. Our results offered the scientific evidence for breast feeding and suggested that additional essential trace elements should be given to cow's milk when it was used to fed infant.