Abstract: OBJECTIVE To investigate the diagnostic value of inflammatory cytokines in patients with sepsis caused by infections. METHODS A total of 130 patients with sepsis in the hospital ICU from Jan. 2015 to Jun. 2017 were selected as experimental group, and 106 patients with non-sepsis in the same period were selected as control group. Peripheral blood procalcitonin (PCT), serum free calcium, C-reactive protein (CRP), N-terminal pro-brain natriuretic peptide (NT-proBNP) and plasma D-dimer (DD) were compared between the two groups, and their correlation with sepsis was analyzed. RESULTS The levels of PCT, NT-proBNP and CRP in experimental group were (27.34±10.82) ng/L, (3652.39±431.26) pg/ml and (125.53±24.66) mg/L, respectively, which were higher than (10.31±4.50) ng/L, (823.43±109.71) pg/ml and (58.32±11.25) mg/L (P<0.05). A total of 130 pathogenic bacteria were detected in septic patients, of which 68 were gram-negative bacteria accounting for 52.31%, mainly Bacillus subtilis and Bacteriocin,35 strains were gram-positive bacteria accounting for 26.92%, mainly Staphylococcus aureus and Staphylococcus epidermidis, and 22 strains were fungi accounting for 16.92%, mainly Candida albicans and Aspergillus. The levels of PCT, NT-proBNP and free calcium in the sepsis group were correlated with APACHEⅡscore (P<0.05), and PCT was strongly correlated with APACHEⅡ. CONCLUSION PCT and NT-proBNP contribute to the early diagnosis of sepsis. PCT and serum free calcium can be used as important indexes to evaluate the severity of sepsis.