Abstract：Objective To preliminarily establish a reference interval of D-dimer levels in late pregnancy women in Jiangbei New District of Nanjing City, and to explore the application value of D-dimer in clinical diagnosis. Methods A total of 1 615 women in late pregnancy who visited the Fourth Affiliated Hospital of Nanjing Medical University from October 1, 2022 to September 30, 2023 were enrolled as the observation group. Additionally, 559 non-pregnant healthy women during the same period were selected as the healthy control group. The P95 value was used as the upper limit of the D-dimer reference interval, to establish the reference interval of D-dimer levels in late pregnancy was established, and the clinical diagnostic significance of D-dimer levels was analyzed. Results The D-dimer values in the observation group were significantly higher compared with the control group （P＜0.05）. Using the P95 value of 4.4 mg/L as the upper limit, the reference interval for D-dimer in late pregnancy was defined as≤4.4 mg/L. No statistically significant difference in D-dimer levels was observed between women aged ＜35 years and those aged≥35 years within the observation group （P＞0.05）. Conclusion A preliminary reference interval for D-dimer levels in women during late pregnancy in Jiangbei New District has been established. D-dimer testing may serve as a useful preliminary screening tool in the prevention and management of venous thromboembolism （VTE）, disseminated intravascular coagulation （DIC）, and postpartum hemorrhage.