Abstract: ObjectiveTo investigate the mortality rate of children and adolescents aged 0-19 years and trend change in Kunshan from 2005 to 2019 and analyze the main causes of death so as to provide evidence for targeted disease prevention and control policy making.MethodsAll cause of death registration data among residents in Kunshan City were collected from 2005 to 2019. Death causes were classified and coded according to international classification of diseases (ICD-10). Excel and Joinpoint Regression Program(4. 8. 0. 1) were used to perform descriptive analysis and tendency judgment.ResultsFrom 2005 to 2019, child and adolescent mortality aged 0-19 years old among Kunshan residents fluctuated from 21. 81 per 100 000 to 63. 99 per 100 000, and the mean crude mortality rate was 39. 32 per 100 000. The crude mortality rate of both males and females showed a descending trend. The top five causes of death were perinatal conditions(8. 14 per 100 000), injury and poisoning(7. 20 per 100 000), congenital deformities and chromosome abnormality(6. 66 per 100 000), neurological disorder(4. 59 per 100 000), and tumor(3. 60 per 100 000). Mortality which caused by the top five causes of death had been declining over the last 15 years.ConclusionThe mortality rate of children and adolescents in Kunshan is relatively low. Perinatal and congenital diseases, injury and poisoning are the main causes of death in local children and adolescents, among which perinatal period and congenital diseases are the main causes in 0 ~ < 5 age group, injury and poisoning are the main causes in 5-19 age group, followed by tumor. A comprehensive and supportive health environment should be established in conjunction with all sectors of society to prevent and control perinatal and congenital diseases, injuries, tumors and other chronic diseases so as to improve the quality of life of children and adolescents in this region.