Objective: To study the rate of allogeneic blood transfusion after total hip replacement (THR) and analyze the related risk factors in order to provide theoretical basis for reducing the amount of allogeneic blood transfusion after THR. Methods: 516 patients who underwent total hip replacement from June 2015 to June 2019 in the First Affiliated Hospital of Zhengzhou University were analyzed retrospectively Allogeneic Transfusion Group (n=102) and non-allogeneic Transfusion Group (n=414) were divided into two groups. The related indexes which might influence the rate of allogeneic transfusion were sorted out and the related risk factors were screened by univariate analysis and logistic regression analysis. The experiment was approved by the Ethics Committee of the First Affiliated Hospital of Zhengzhou University in July 2019. Results: ⑴ Of 516 total hip replacement patients, 102 patients underwent allogeneic transfusion due to anemia, the allogeneic transfusion rate was 19.8%. ⑵ The results of single factor analysis showed that There were significant differences in sex, age, preoperative diagnosis, hypertension grade, preoperative hemoglobin concentration, intraoperative unilateral and bilateral operation, drainage tube placement or not, and postoperative calcium concentration between allogeneic transfusion group and non-transfusion group (P＜0.05). ⑶ Further analysis showed that preoperative diagnosis was primary or secondary osteoarthritis and rheumatoid arthritis (OR=4.868, P=0.001), hypertension above grade 2 (OR=8.053, P＜0.001), preoperative hemoglobin Concentration (OR=0.949, P=0.001), one-stage bilateral surgery (OR=7.322, P＜0.001), placement of the intraoperative drainage tube (OR=1.911, P=0.016) and postoperative calcium concentration (OR=0.198, P=0.003) is an independent risk factor for postoperative allogeneic blood transfusion. Conclusion: Primary/Secondary Osteoarthritis (OA) and rheumatoid arthritis (Ra) , pre-operative hypertension above grade 2, low hemoglobin concentration before operation, one-stage bilateral total hip arthroplasty, intraoperative drainage tube placement and reduced calcium concentration after operation are important risk factors of allogeneic blood transfusion after total hip arthroplasty.