Objective To explore the influence of tranexamic acid used in different modes in total hip arthroplasty (T HA ) blood loss by control experiment .Methods 60 patients accepted total hip arthroplasty from orthopaedics in our hospital were se‐lected between March 2010 to August 2013 ,among them femoral neck fracture were 47 cases and 13 cases were osteonecrosis .aged between 45‐82 years old ,and 62 in average .All gave unilateral total hip arthroplasty .All patients were divided into three groups ,A group(contradistinction group) ,B ,C group(experiment group) .each groups include 6 men and 14 women ,no revision surgery pa‐tients .For group A ,100 mL normal saline was dripped both in half on hour before surgery and 3 hours after surgery ;For group B , tranexamic acid diluted in 100 mL normal saline according to 10 mg/kg was dripped half on hour before surgery ,100 mL normal sa‐line was dripped 3 hour after surgery ;For group C ,tranexamic acid diluted in 100 mL normal saline according to 10 mg/kg was dripped both half on hour before surgery and 3 hour after surgery .Compute and record the visible blood cell loss and hidden blood loss ,the comparative analysis was conducted to discuss the effectiveness and safety of tranexamic acid used in the two methods .Re‐sults The visible blood cell loss in each group were (196 .20 ± 44 .45)mL ,(114 .84 ± 35 .21)mL and (104 .47 ± 30 .01)mL ;hidden blood loss in each group were:(614 .50 ± 98 .41)mL ,(425 .74 ± 70 .01)mL and (337 .12 ± 52 .23)mL .Conclusion In the unilateral total hip arthroplasty ,the use of tranexamic acid can significantly reduce a significant amount of visible and hidden blood loss .Com‐pared with tranexamic acid dripped just half one hour before surgery ,dripping tranexamic acid both half one hour before surgery and 3 hour after surgery reduced more hidden blood loss ,decreased transfusion requirement ,and this does not significantly increase the risk of deep venous thrombosis .