China Kadoorie Biobank (CKB) conducted the baseline survey from June 2004 to July 2008 in five rural areas in Zhejiang, Hunan, Gansu, Sichuan and Henan Provinces and five urban areas in Heilongjiang, Shandong, Jiangsu, Guangxi and Hainan Provinces (Autonomous Region). A total of 512 891 adults aged 30-79 years were recruited in the baseline survey, i.e. questionnaire survey, physical examination and blood sample collection. The first resurvey of 19 786 people was conducted from June to October in 2008, and the second resurvey of 25 239 people was conducted from August, 2013 to September, 2014. In 2016, with the support of the "Precision Medicine Research" Key Project, National Key Research and Development Program of China, CKB started a large natural population cohort demonstration study on the basis of the previous work. The third resurvey was conducted from August, 2020 to December, 2021 among 25087 people, including questionnaire survey (with additional aging related items), physical examination and biological sample collection (blood, urine, saliva, stool). By June, 2022, CKB had conducted the follow up in cohort population for an average 15 years, resulting an observation of 7.7 million person-years. which documented 74 000 deaths, 371 000 health insurance events (2.795 million episodes in total), 11 000 active follow-up events (12 000 episodes in total), 100 000 morbidity monitoring events (147 000 episodes). CKB Biobank has stored 1 292 000 blood samples, 150 000 urine samples, 780 000 DNA samples, 25 000 saliva samples, and 20 000 stool samples. CKB project team has developed the technical specifications for long-term follow-up, sample database construction and management, database and data sharing platform construction and management, which have been compiled and published as the Technical Specifications for Large Population Cohort Research. In addition, the group standards of field survey of large natural population cohort, long term follow up, biobank construction, data process and data security have been developed. Meanwhile, high-quality scientific research have been conducted consecutively based on the CKB cohort data, the research of the relationship between healthy lifestyle and major chronic diseases have provided specific evidence in Chinese population.
