This study aimed to analyze the changes of C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) measured in acute infection within four weeks post artificial joint surgery to predict potential infection in early stages, provide rapid treatment, and prevent the abuse of antibiotics. This study included 50 patients with acute infection and 50 patients without any symptoms of infection, among patients who received artificial joint replacement surgery on the lower limbs in a four-week period. CRP was the highest two-to-three days after surgery. with 5.77±3.69 and 5.17±3.48, respectively, in those with infection and without infection. Thereafter, the value rapidly reduced in those without infection. However, it increased again to 3.16±2.87 in the group with infection according to the bimodal curve (p<0.001). ESR was the highest two-to-three days after surgery, with 58.8±24.63 and 44.08±21.48, respectively. Thereafter, the value slowly reduced in those without infection. However, it was increased again to 47.62±26.26 in those with infection according to the bimodal curve p<0.001). As this study shows, if there is an increasing trend for CRP and ESR after artificial joint replacement surgery, it may be possible to question whether patients are acutely infected post surgery. In particular, this result is expected and regarded as a useful factor for diagnosing infection due to the high level of sensitivity and uniqueness for CRP.