Background: Genetic polymorphisms, age, gender and body weight are major determinants of warfarin dose requirements. Our previous study showed that patients with non-O blood groups required higher doses of warfarin than those with O blood groups. However, the underling mechanism was not well known.Objectives: The study aimed to investigate the influence of ABO blood group, age and gender on the values of coagulation tests in patients with acute deep vein thrombosis in Chinese Han population.Methods: A retrospective study was conducted in the First Affiliated Hospital of Shantou University Medical College in Southern China. Two hundreds and 35 patients with confirmed diagnosis of acute deep vein thrombosis were included. Coagulation tests were determined.Results: Of 235 patients with acute deep vein thrombosis of lower extremities, 70 patients had blood group A (29.79%), 71 patients had blood group B (30.21%), 30 patients had blood group AB (12.77%), and 64 patients had blood group O (27.23%). The study showed no difference about coagulation tests among the patients with different blood groups. Coagulation tests were not affected by age and gender.Conclusion: Our study showed that ABO blood group, age and gender had no effects on coagulation tests in patients with acute deep vein thrombosis