ObjectiveTo evaluate diagnostic value and clinical significance of procalcitonin (PCT)  in infection in intensive care unit (ICU) patients. Methods96 ICU patients in a hospital between September 2011 and March 2012 were selected for study, levels of patients’ PCT, highsensitivity Creactive protein (HsCRP)  and white blood cell (WBC) count were detected, statistical analysis were conducted. ResultsCompared with nonbacteria infected patients, serum PCT and HsCRP levels in all bacteria infected patients increased, the difference were significant (Z=-6.102;-3.918，both P＜0.05 ); WBC count was not significantly different（Z=0.212.P＞0.05）.PCT sensitivity, specificity, positive predictive value, and negative predictive value for diagnosing infection was 82.35%，67.86%，86.15%，and 61.29% respectively; receiver operating characteristic (ROC) curve of PCT, HsCRP, and WBC was 0.898, 0.755, and 0.581 respectively. ConclusionThere are higher sensitivity and specificity of PCT to predict infection, which is helpful for early detection of infection in critically ill patients.