Objective：The aim of this trial is to assess effects of Kieember and Yashili infant formula on body growth, behavior development, intestinal comfort, infectious diseases, allergic diseases, the absorption of nutrients and gut microbiota as compared to breast-milk in term infants aged 0-3 months.

Participants：144 healthy term infants aged less than 30 days at entry to study. Study Design: A open-label,parallel, controlled trial.

Arms, Groups, and Intervention: (1) Breast milk-fed group: fed with human breast milk; (2) Breast Milk Simulated Formula Group：fed with breast milk simulated infant formula (Ruibuen®Kieember, Phase I); (3) Traditional Formula Group: fed with traditional infant formula (Ruibuen®Yashili, Phase I).

Intervention Duration: 90 days.

Visits: 1month and 3month old.

Outcome measures: (1)Biochemical detection of feces (total fat, fatty acids, calcium, nitrogen);(2)Stool characteristics (frequency, color, volume, and stool consistency);(3)Anthropometric parameters (body length, body weight, and head circumferences);(4)Temperament and adaptive behavior;(5)Gut microbiota;(6)General health and wellbeing;(7)concomitant medications and adverse events.

Inclusion Criteria:

• Term infant: Born at 37-42 gestation weeks
• Birth weight: 2500-4000g (appropriate for gestational age)
• The infant is in good health and Apgar after 5 minutes >7
• The mother had unequivocally decided not to breastfeed (for formula fed infants) or to breastfeed (for human milk fed infants)
• age at the enrollment: less than 30 days

Exclusion Criteria:

• The mother is unable to take care of her infant on account of health condition (psychological or physical) or socioeconomic problems
• The infant is born with a congenital malformation or chromosome abnormality with a clinical significance
• The infant suffers from a disease requiring mechanical ventilation or medication in the first week of life (not including applying phototherapy of blue to cure neonatal jaundice)
• The infant whose feeding or normal metabolism is affected by any suspected or unknown metabolic factors or physical limitations
• The infant has been breastfed for more than 2 weeks (for formula fed infants)
• Twins or multiple births