Objective To investigate the effects of different feeding patterns on the intellectual development and immune function of infants, so as to provide evidence for scientific feeding of infants. Methods Totally 87 healthy full-term infants born in Dalian Maternal and Child Health Hospital from May 2019 to June 2020 were enrolled in this study, and were divided into breast feeding group and artificial feeding group.Serum IgG, IgM and IgA tests were performed at 3, 6 and 12 months of age.Intellectual development was assessed at 6 and 12 months of age. Results At 6 months old, the developmental quotient, the scores of fine movement, language and social behavior of infants in the breastfeeding group were significantly higher than those of the artificial feeding group (t=2.035,3.814, 2.075, 2.229, P<0.001 or ＜0.05).At the age of 12 months old, the developmental quotient, the scores of fine movement and language of infants in the breastfeeding group were significantly higher than those of the artificial feeding group (t=2.062, 2.271, 2.066, P＜0.05).Serum IgG level of infants in the breastfeeding group was significantly higher at 6 months old than that of the artificial feeding group(t=4.920, P＜0.001),but there was no significant difference between the two groups at 3 and 12 months old(t=0.316,0.708, P＞0.05).Serum IgM level of infants in the breastfeeding group was significantly higher at 6 and 12 months old than that of the artificial feeding group (t=2.700, 4.757, P＜0.01), while there was no significant difference between the two groups at 3 months old (t=1.797, P=0.076).Serum IgA level of infants in the breastfeeding group were higher than that of the artificial group at 3, 6 and 12 months old (t=6.441, 6.115, 6.765, P<0.001). Conclusions There are differences in intellectual development and immune function in infants with different feeding patterns.Breastfeeding is beneficial to the intellectual development and immune function of infants, and should be strongly supported and promoted.