Abstract: OBJECTIVE To analyze the distribution, drug resistance of the pathogenic bacteria and immune function of patients hospitalized in intensive care unit (ICU) with mult-drug resistant organism (MDRO) infection. METHODS A total of 96 cases of patients hospitalized in ICU from Jan. 2014 to Dec. 2016 were selected as the observation group, and 100 healthy people were selected as the control group. The distribution of pathogenic bacteria, the infection condition and drug resistance of MDRO in the infected patients were analyzed. The indicators of T lymphocyte subgroups in the peripheral blood of the subjects in the two groups were compared. RESULTS There were 26 cases of infections in the observation group, with the infection rate of 27.08%, and the 61 case-time were infected. The distribution of infected sites was mainly in the lower respiratory tract. Totally 76 strains of bacteria were isolated, in which, 51 strains were gram-negative bacteria accounting for 67.11%, mainly Escherichia coli and Acinetobacter baumannii, and 25 strains were gram-positive bacteria accounting for 32.89%, mainly Enterococcus faecalis and Staphylococcus aureus. A total of 40 strains of MDRO in the pathogenic bacteria were detected. The drug resistant rates of gram-negative pathogens of MDRO to most antibacterial agents were higher, and E. coli was less resistant to imipenem and meropenem. The drug resistant rates of gram-positive pathogens of MDRO to most antibacterial agents were higher, and the strains resistant to vancomycin, teicoplanin or linezolid were less. The CD₃⁺, CD₄⁺, CD₈⁺ and CD₄⁺/CD₈⁺ in the peripheral blood of the patients in the observation group were (62.28±4.75)%, (33.16±5.06)%, (26.64±3.34)% and (1.28±0.29), which were lower than those in the control group (P<0.05). CONCLUSION The MDRO strains have strong resistances to most antibiotics in the patients hospitalized in ICU. The clinicians should pay more attention and select sensitive antibiotics for treatment according to the results of drug sensitivity test.