Objective:To explore the early diagnostic value of serum procalcitonin(PCT),C-reactive protein (CRP) and endotoxin in patients with sepsis caused by bacterial bloodstream infection.Methods:Retrospectively analyzed 123 cases of patients diagnosed with sepsis induced by bacterial bloodstream infection in our hospital from May 2010 to May 2015,detected their serum PCT,CRP and endotoxin levels,and analyzed the evaluation value of these three indexes for sepsis induced by bacterial bloodstream infection by receiver-operating characteristic curve (ROC).Results:Blood sample culture results showed that 123 cases of bacterial bloodstream infections caused by sepsis patients in the presence of infection of G+bacteria were 35 cases,G-bacteria infection of 88 cases;The levels of three index in the G+bacteria group were significantly lower than that in the G-bacteria group (P＜0.05);The serum PCT,CRP and endotoxin levels was positive correlated with each other among G+bacteria group,G-bacteria group and all bacteria group;ROC curves showed that the cutoff value of serum PCT,CRP and endotoxin for diagnosis of patients with sepsis induced by G+bacteria bloodstream infection were 1.58 μg/L,95.25 mg/L and 16.71ng/L,and their sensitivity and specificity were (65.92％,88.37％),(67.39％,84.38％) and (56.34％,78.93％) respectively;and the cutoff value for diagnosis of patients with sepsis induced by G-bacteria bloodstream infection were 2.45 μg/L,79.45 mg/L and 15.54 ng/L,their sensitivity and specificity were (78.73％,97.13％),(68.89％,92.38％) and (65.39％,95.33％)respectively.Conclusion:Detecting the serum PCT,CRP and endotoxin levels is helpful to identify patients with sepsis induced by G+ or G-bacteria bloodstream infection,with high sensitivity and specificity,which can be used in the early diagnosis of sepsis induced by bacterial bloodstream infection.