Objective To investigate infectious complications and analyze their risk factors in patients with systemic lupus erythematosus (SLE) and provide clue for antibiotics treatment. Methods Patients with SLE admitted to our hospital between 2002 and 2007 were. reviewed, and the characteristics of their infections including the infection sites, pathogens and the drug resistance of pathogenic bacteria were investigated. The suspected risk factors of infections in patients with SLE were selectod and then analyzed by chi-square test and Logistic regression. Results The prevalence of infection in this group of patients was 24.4% (130/533). One patient died from respiratory tract infection. The common infection sites were respiratory tract (56.9%), urinary tract (23.8%) and skin (18.5%). Bacteria were the most common pathogens of infections in SLId pa-tients (53.3%), the majority of which were gram-negative bacteria. The second major pathogen was fungus (39.2%), and the third was the combination of bacteria and fungus. There were 7 patients with tuberculosis. The common strains causing infections in SLE patients were. Escheriehia coli, Klebsiella pneumonea, Pseu-domonas aeruginosa, Staphylococcus aureus and Candida albican. Antimicrobial susceptibility tests showod that the drug resistant rates increased rapidly. The gram-negative ones were sensitive to eefoperazone-sulbac-tam and carbopenems. The infection-related risk analysis suggested that the independent risk factors of infections in SLE patients included old age, hypopruteinemia, moderate anemia and high dose of eorticos-teruids treat-ment. Conclusion Those patients with infection-related risk factors should be monitored closely for infec-tions. Respiratory tract and urinary tract are the most common infectious sites in SLId patients, and gram-nega-tive bacteria are the major pathogens, so antibiotics such aa cefoperazone-sulbactam or carbopenems may be good choices before the result of antimicrobial susceptibility test information is available.