Abstract: OBJECTIVE To study the clinical values of C-reactive protein (CRP), serum procalcitonin (PCT) and endotoxin in the early diagnosis of sepsis caused by bloodstream infection of gram-negative (G-) bacteria, so as to provide references for clinical treatment. METHODS A total of 112 patients with sepsis in the ICU of the hospital were selected from Jun.2012 to Feb. 2016. According to the bacterial culture results, the patients were divided into gram-positive bacteria group with 29 cases (G+) and gram-negative bacteria group with 83 cases (G-). The levels of inflammatory cytokines in sepsis patients with bloodstream infection were compared. RESULTS The levels of serum PCT, endotoxin and CRP in G- group were all higher than those in G+ group (P<0.05). The levels of endotoxin and PCT, CRP and PCT, endotoxin and CRP in G+ group, G- group and all patients in bacterial group had positive correlations (P<0.05). G-, G+ specificity, area under the curve and sensitivity were higher. CONCLUSION The levels of PCT, endotoxin and CRP were higher in patients with sepsis caused by G- bloodstream infection than those with G + bloodstream infection, and the three indexes had important clinical significances in the early diagnosis of sepsis caused by G-bloodstream infection.