Objective To know about the screening situation of early warning signs of psychological behavior in infants aged 24 months,and to explore the possible influencing factors,so as to provide reference for the effective screening in clinic. Methods A total of 2 731 infants born in 2016 were selected by random sampling in 5 counties across the 4 provinces in China,and the basic information of maternal and infants,feeding conditions,growth and health conditions were collected by follow-up survey.The national early warning sign screening table was used to screen children with mental behavior retardation. Results The positive screening rate of psychological behavior early warning signs in 2-year-old children was 6.65%,and significant differences existed between different gender and region groups(P<0.05).The results of single-factor analysis showed that there were significant differences on the positive rate of psychological behavior early warning signs among children with different breast-feeding duration,family living environment,outdoor activities and interaction time (P<0.05).Logistic regression analysis showed that boys (OR=2.169,95%CI:1.516―3.103),living in northern China (OR=2.308,95%CI:1.630―3.267),breastfeeding less than 6 months (OR=1.645,95%CI:1.088―2.489),and children′s outdoor activities less than 4 hours (OR=2.715,95% CI:1.548―4.761) were risk factors for the positive results of early warning screening in 2-year-old children. Conclusions It is suggested to pay more attention to early psychological behavior screening,early detection,early referral,early intervention in infants.In addition,parents are encouraged to promote breastfeeding,share more time to accompany infants and take part in outdoor activities,thereby facilitating the healthy growth of children.