The healthy life trajectories initiative (HeLTI) is a prospective birth cohort intervention study led by the World Health Organization (WHO), which involves multiple countries including China, Canada, South Africa, and India. The project aims to explore and establish community-family-maternal-child (CFMC) intervention measures that cover multiple stages such as pre-pregnancy, pregnancy, infancy and early childhood by the advantages of HeLTI in personalized health education and authoritative professional health guidance. It aims to implement continuous and multi-level interventions to build an international collaborative research platform, and to achieve the goal of preventing developmental diseases such as obesity from the earliest stage of life. The life tree project (Sino Canadian health life trajectories initiative, SCHeLTI) is jointly funded by the National Natural Science Foundation of China (NSFC) and the Canadian Institutes of Health Research (CIHR). It is led by the International Peace Maternal and Child Health Hospital, and has formed a research team with well-known universities and institutions such as Xinhua Hospital, Fudan University Obstetrics and Gynecology Hospital, and Sherbrooke University in Canada. The project is mainly implemented in 42 community health service centers in Xuhui District, Changning District, Minhang District, Fengxian District, and Songjiang District of Shanghai. The multi-level comprehensive interventions in this project will be promoted in Shanghai and even throughout the whole China, and provide scientific basis for WHO to develop intervention guidelines for childhood obesity.