Abstract: Objective:To explore the changes of bacterial spectrum and its resistance in pediatric sepsis so as to provide basis for correct use of antibiotics. Methods:The bacteria strains detected in the blood culture of children suffering from sepsis from 2005 to 2010 and the drug sensitivity were studied retrospectively. The patients admitted from 2005 to 2007 were included in Group A and patients admitted from 2008 to 2010 were in group B. The changes of bacterial spectrum and the drug resistance were compared between the two groups. Results:Five hundred and eighty-two strains were isolated,among which the Gram-positive bacteria accounted for 358 (61.5%),the Gram-negative bacteria 188 (32.3%),the Candida 8 (1.4%) and others 28 (4.8%). The major strains included coagulase-negative Staphylococci(51.2%),Escherichia coli(20.4%),Staphylococcus aureus(6.4%),Klebsiella pneumoniae(3.4%) and Enterobacter(3.4%). The drug resistance of group B to common antibiotics was higher than that of group A; meanwhile,the positive strains of extended-spectrum β-lactamases had a tendency to increase. Conclusions:The gram-positive bacterium is the main pathogen in pediatric septicemia and has a tendency to increase. With the application of broad-spectrum antibiotics,the drug resistance increases significantly.