Abstract： Objective:To comprehensively analyze the age, period, and birth cohort characteristics of hand, foot, and mouth disease (HFMD) among children aged 0-9 years in China from 2009 to 2019 using the age-period-cohort (APC) model.Methods:HFMD incidence among children aged 0-9 years from 2009 to 2019 was collected from the Public Health Science Data Center and analyzed using the APC model. The average annual percentage change (AAPC) was used to evaluate trends in HFMD. The relative risk (RR) of period and cohort effects was calculated with 2014 and 2010 as references.Results:From 2009 to 2019, the incidence of HFMD in China showed an upward trend, with AAPC as 3.28% (95% CI: 1.27%-5.32%). The differences between AAPC of age groups and the overall AAPC were not statistically significant ( χ2=2.17, P=0.995). After adjusting for age and cohort effects, the incidence rate of HFMD showed a pattern of higher incidence in even years and lower incidence in odd years, with the highest incidence rate (1 753.35/100 000) in 2014. The overall cohort effect was not statistically significant ( χ2=12.22, P=0.836) after adjusting for age and period effects. However the risk of HFMD was higher in the population born from 2012 to 2018 (RR>1, P<0.05) using data in 2010 as reference. After adjusting for period and cohort effects, the incidence rate of HFMD in the 1-year-old group was the highest (3 341.28/100 000). After 1 year of birth, the RR decreased by 0.59 (95% CI: 0.54-0.64) for each additional year of age. Conclusions:HFMD among children aged 0-9 in China shows distinct age, period, and cohort characteristics, which could be used to guide the implementation of differentiated prevention and control measures.