Objective：To analyze the related factors influencing serum 1，5 - anhydro - D - glucitol（1，5 - AG）levels and establish reference intervals. Methods：A total of 873 participants，aged 20 to 72 years，were enrolled from an epidemiological survey conducted between August and November 2021 in Nanjing，Jiangsu Province，and surrounding areas. Questionnaire survey，physical examination， and detection of routine clinical blood indicators including serum 1，5-AG were performed. Participants were categorized into different disease groups according to inclusion and exclusion criteria. Student’s t-test was used to compare serum 1，5-AG levels among these groups. Pearson correlation analysis and multivariate linear regression were employed to assess associations between serum 1，5-AG and various clinical parameters. The reference interval for 1，5-AG was determined based on the 5th percentile among the apparently healthy population. Results：Serum 1，5-AG levels were significantly associated with sex，body mass index（BMI），body roundness index（BRI），fasting blood glucose，fasting insulin，2 - hour postprandial blood glucose，glycated hemoglobin（HbA1c），estimated glomerular filtration rate（eGFR），total cholesterol，and carbohydrate-derived energy intake（all P ＜ 0.05）. Nine groups were screened from the study subjects：apparently healthy group，diabetes mellitus group，hypertension group，hyperlipidemia group，impaired fasting glucose group，impaired glucose tolerance group，hepatic dysfunction group，renal dysfunction group，and obesity group. Significant differences in 1，5-AG levels were observed between the apparently healthy group and the hyperlipidemia，hepatic dysfunction，and obesity groups. Based on the 5th percentile，the reference intervals of 1，5-AG were set as ＞ 99.8 μmol/L for males and ＞ 62.9 μmol/L for females. Conclusion：Serum 1，5-AG levels are associated with individual glycemic status，lipid metabolism，and dietary patterns， and are influenced by age，sex，renal function，and dietary composition. The sex - specific reference intervals for serum 1，5 - AG established in this study provide a valuable tool for monitoring glycemic variation and guiding the clinical management of diabetes.