ObjectiveTo observe the changing patterns of erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and serum amyloid A protein (SAA) levels before and after hip replacement surgery, and explore their clinical significances. MethodsNinety-seven consecutive patients enrolled in clinical pathway in our hospital for hip replacement from April 2011 to May 2013 were included in the present study. ESR, CRP and SAA levels were investigated preoperatively and post-operatively at day 1, 3, 5, 7, 14, Month 1 and 3. All the cases were followed up, among which there were 14 cases of total hip replacement, 56 cases of cementless hemianthroplasty, and 27 cases of biotype hemianthroplasty. ResultsAll three of ESR, CRP and SAA levels were elevated post-operatively. Levels of CRP and SAA peaked at day 3 after surgery, and then subsided gradually to pre-operative levels after 1 month. ESR level peaked at day 7 postoperatively, and then subsided gradually to pre-operative levels after 3 months. There was a significant correlation between levels of CRP and levels of SAA. ConclusionCompared with ESR and SAA, CRP appears to be a faster and more sensitive parameter. Cementless hemianthroplasty is associated with changes of SAA levels but not with CRP levels. Close monitoring of evolutionary changes in ESR, SAA and CRP levels may help to diagnose and treat early infection after hip replacement surgery.