Objective To analyze the sleep status of infants and young children aged 0～35 months,in order to understand the common sleep problems and possible influencing factors of infants and young children.Methods Healthy infants aged 0～35 months who underwent physical examination in the outpatient Department of Child Health Care,Kunming Children's Hospital from June 2022 to May 2023 were selected as the study subjects.The brief infant sleep questionnaire(BISQ)was completed by their parents.Single factor analysis and Logistic regression analysis were used to analyze the sleep status of infants and young children and the factors affecting sleep problems.Results The primary sleeping mode for infants and young children is sleeping with parents(85.6%).The average daytime sleep duration is(3.51±1.75)hours,nighttime sleep is(8.84±1.41)hours,and total daily sleep is(12.37±2.07)hours.Daytime and total sleep duration decrease gradually with increasing age in each age group(P<0.05).27.7%of infants and young children may experience insufficient sleep duration;the prevalence of sleep problems is 79%,with the highest rate of difficulty falling asleep at 75.3%,followed by night waking(72.2%)and sleep rhythm disturbances(19.7%);278 cases(92.7%)involve involuntary falling asleep.Univariate analysis shows that age and sleep initiation method are related to the occurrence of sleep problems in infants and young children(P<0.05).Logistic regression analysis suggests that young age and involuntary falling asleep are risk factors for the occurrence of sleep problems.Conclusion The incidence of sleep problems in infants and young children is high,which is related to the young age and involuntary sleep onset.It is recommended to train infants and young children to fall asleep autonomously as early as possible,and strengthen the education of sleep habits in infants and young children to reduce the incidence of sleep problems in infants and young children.