Objective · To investigate the developmental state of infants in early childhood and identify risk factors for their early development in community.  Methods · Cluster sampling was conducted to collect data of infants aged 12 months by Denver Developmental Screening Test (DDST) in Shanghai Jing’an District. Logistic analysis was employed to detect factors influencing the intellectual development of infants.  Results · A total of 4 102 infants were enrolled in the survey. The prevalence for abnormal screening result was 1.0%, while 4.3% for suspicious abnormal result. Logistic analysis revealed that low birth weight (OR=6.24, 95% CI 1.69-22.98, P=0.006), low head circumference (OR=5.22, 95% CI 1.20-22.84, P=0.031), mothers older than 35 years in pregnancy (OR=3.61, 95%CI 1.32-9.84, P=0.012) or history of brain impairment (OR=3.96, 95% CI 1.55-10.10, P=0.003) were the risk factors for abnormal screening result. Spearman rank correlation analysis showed a significant negative relationship between breastfeeding duration and suspicious abnormal screening result (ρ=-0.031, P=0.046).  Conclusion · It is essential to draw attention to early developmental screening and interference, especially to infants with mothers older than 35 years in pregnancy, low birth weight, low head circumference or high-risk infants. Breastfeeding is helpful for decreasing detection rate of abnormal result.