Objective: To analyze the characteristics of opportunistic infections(OIs) in patients with HIV/AIDS in Nanjing and the relationship between the frequency of OIs and the CD4+ T lymphocyte counts. Methods: The characteristics of 187 hospital patients with HIV/AIDS were retrospectively analyzed. These patients were admitted into the Department of Infectious Disease of the Second Hospital of Nanjing from 2004 to 2009. Results: Among 187 patients,109 (58.29%) had OIs,with 263 episodes totally. The prevalence in patients with baseline CD4+ cell counts ≥200 cells /μl(9.38%,6/64) was significantly lower than that in patients with CD4+ cell < 200 cells/μl (83.74%,103/123) (χ2 = 95.75,P < 0.05). The multivariate Logistic analysis showed that the baseline CD4+ counts of patients were significantly related to OIs(OR = 0.977,P < 0.001). With the CD4+ counts continuous were declining,the proportion of clinical symptoms and OIs of patients were gradually rising. Conclusion: The most common OIs in patients with HIV/AIDS were respiratory infections,oral candidacies,Pneumocystis carinii pneumonia(PCP),tuberculosis and viral herpes. In the course of daily treatment,the CD4+ cell counts should be periodically detected,relevant prevention measures of infections should be given,and follow-up and information management should be strengthened.