Abstract:[Objective]To investigate the effects of two negative pressure drainage placement methods on blood loss and erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) after primary total hip arthroplasty (THA).[Methods]A retrospective analysis of 200 patients who underwent primary total hip arthroplasty in our department from March 2014 to May 2019 was carried out. They were selected strictly according to the inclusion and exclusion criteria. Among them, 65 patients in group A (drainage tube placed in articular capsule) and 135 patients in group B (close suture of articular capsule and placement of drainage tube outside articular capsule).The general data, preoperative blood routine, CRP, ESR, intraoperative blood loss, 1 and 3 days postoperatively, CRP and ESR levels, postoperative drainage, local infection, hematoma formation and blood transfusion were collected from 200 patients in the two groups. According to the collected data, the total blood loss and occult blood loss of the two groups were calculated and analyzed statistically.[Results]There was no significant difference in the general data before operation between the two groups (p>0.05). There were no cases of local infection, hematoma formation and blood transfusion after operation.In group A,total blood loss on the first day and the third day after operation，the volume of induced blood flow and dominant blood loss were significantly higher in group B,but the occult blood loss in group A was less than that in group B (P<0.05);The level of Hb in group A was lower than that in group B on the first day after operation (P<0.05);The change of Hb in group A was significantly higher than that in group B on the first day and the third day after operation (P<0.05).[Conclusion]The joint capsule was sutured tightly and drained in the primary total hip arthroplasty. Compared with conventional intracapsular drainage, the total blood loss after operation is less, but the hidden blood loss increased, and the level of inflammation index increased.