Objective To investigate the effect of prone time on motor development in infants. Methods The infants aged 3 to 11 months old were evaluated using the Peabody motor scales and their prone time per day was collected. Results 152 infants were enrolled. There were 43 cases in control group (prone time <0.05). Conclusions Prone time in infants was significantly correlated with gross motor development. Parents should be encouraged to interact with their babies in the prone position during waking hours.