Importance: There was little data on the distribution of blood glucose levels and diabetes prevalence for centenarians and the oldest-old. Objective: The aim of this study is to analyzed the distribution of blood glucose and diabetes prevalence for centenarians and oldest-old in China:Based on the China Hainan Centenarian Cohort Study (CHCCS) and China Hainan Oldest-old Cohort Study (CHOCS). Design, setting and participants A total of 1002 centenarians and 798 oldest-old were enrolled from 18 cities and counties in Hainan Province (one of the longevity provinces). Main Outcomes and Measures: The fasting blood glucose was tested and prevalence of diabetes was calculated. Results: The average age of centenarians was 102.77±2.55 years old, 82.0% were women. The average age of the oldest-old was 84.99±4.01 years old, 59.9% were women. The average blood glucose of centenarians was 5.12±1.44mmol/L and 4.80±1.27mmol/L, and more than 70% were between 3.00mmol/L and 5.99mmol/L. There was no statistical difference between different genders and age groups. A total of 9.5% of centenarians had diabetes and 8.1% had IFG. A total of 11.4% of the oldest-old had diabetes and 4.4% had IFG. Abdominal obesity and TG levels may be associated with diabetes prevalence. The corresponding ORs were 1.517(1.083-2.125) and 1.473(1.089-1.943) respectively of abdominal obesity among centenarians and the oldest-old respectively, and corresponding ORs 1.182(1.081-1.316) and 1.162(1.009-1.699) respectively of abdominal obesity among centenarians and the oldest-old respectively Conclusions and Relevance: In summary, the results based on CHCCS with the largest sample among centenarians and CHOCS showed that the blood glucose level and the prevalence of diabetes were at a lower level than those of adults or younger elderly. Funding Statement: This work was supported by National Natural Science Foundation (81703285,81773502,81703308), Beijing Nova Program (Z181100006218085), Excellent youth project (2018-yqpy-003); 3+1 project; National Clinical Research Center for Geriatrics Diseases(NCRCG-PLAGH-2017017),Medical big data research project of PLA General Hospital (2018MBD-029, 2018MBD-030); National key research and development project (2016YFC1303603, 2018YFC2000400); National Science and technology resource sharing service platform plan project (YCZYPT[2018]07) Declaration of Interests: The authors declare that there is no duality of interest associated with this manuscript. Ethics Approval Statement: This study was approved by the Biomedical Ethics Committee of Chinese PLA general hospital, and written informed consent with signature or fingerprint was obtained from each respondent.