Abstract: Objective To observe and analyze the behavioral behavior of 3-month-old infants and their mothers during feeding and to provide a basis for constructing an early mother-to-child interaction evaluation model in China.Methods 11 pairs of 3 month old babies and their mothers were selected as research objects. The videos of the mother and infant feeding process were collected in the behavior observation room of the child health clinic and at home. According to the Field's Interaction Rating Scale(Interaction Rating Scale,IRS),a behavioral observation model was established. The behavior of mothers and infants during feeding was evaluated through video behavior coding,and the behavioral differences between mothers and infants in different environments was described.Results During the feeding of 3-month-old infants,the observed more frequent interaction behaviors of mothers was: vocalization to the infant(81.8%),gazing at the infant(72.7%),and touching the infant(72.7%). The top three behaviors of infant were: physical activity(72.7%),stopping sucking halfway(72.7%),gazing at mother(63.6%),and vocalization(63.6%). The incidence of maternal gaze behavior in the observation room(90.9%) was higher than that in the family(72.7%). The proportion of vocalization behaviors in the observation room(27.3%) was lower than that in the family(63.6%).Conclusion The interactive behaviors of mothers and infants during feeding are mainly expressed in three dimensions: expression,language,and movement. Among them,gazing,vocalizing and touching infant or infant's limb movement can be the main observation indicators of mother-infant interaction in three dimensions during feeding. The occurrence of interactive behaviors may be influenced by the observed environment.