Objective To evaluate the correlation between serum procalcitonin concentration and systemic inflam-matory response syndrome (SIRS)score in patients with bacterial bloodstream infection.Methods In January-De-cember,2012,96 patients with bacterial bloodstream infection in a hospital were selected as trial group,and these patients were divided into three groups(group A,B and C)according to SIRS score;84 patients without bacterial in-fection was as control group,PCT concentration of all patients were detected,and the correlation between PCT con-centration and SIRS score was analyzed.Results Among 96 patients with bacterial bloodstream infection,7 (7.29%)died (4 were in group B and 3 in group C);there was no death case in control group.PCT concentration in control group,group A,B and C of trial group were (0.28±0.09)ng/mL,(0.63±0.13)ng/mL,(3.68±1.01)ng/mL,and(7.45±1.53)ng/mL,respectively,the difference between each group was significant(P<0.01).Pairwise comparison of four groups showed statistical difference (P<0.001).Spearman correlation analysis on PCT concen-tration and SIRS score was conducted,correlation coefficient r=0.874(P<0.001)suggested positive correlation be-tween serum PCT concentration and SIRS score.Conclusion PCT concentration in patients with bacterial blood-stream infection and SIRS score is positively correlated,PCT concentration and SIRS score can be used as two mark-ers for assessing the extent and prognosis of bacterial bloodstream infection.