Objective      To analyze the mortality

leading cause of deaths and change trend of the causes in the children under 5 years old in Chongqing during the year of 2006 to 2015. Methods      The data used in this study were collected from the population-based National Maternal and Children Health Surveillance Network of Chongqing. Under-5-mortality rate (U5MR) and the leading causes of deaths for children under 5 years old were analyzed in Chongqing. Results      From the year of 2006 to 2015

the U5MR was decreased from 13.5‰ to 10.1‰

infant mortality from 10.7‰ to 6.9‰

and neonatal mortality rate from 7.3‰ to 4.2‰. The top 5 leading causes of death for children under 5 years old in 2015 were congenital heart disease

premature birth/low birth weight

pneumonia

drowning and birth asphyxia. The proportion of mortality due to congenital heart disease was increased year by year

and the mortality rate of other leading causes were decreased. Conclusion     The leading causes for U5MR in Chongqing are declined remarkably from 2006 to 2015. The proportion of mortality due to congenital heart disease is increased obviously

and those of pneumonia and birth asphyxia are in a downward trend.