Abstract: OBJECTIVE To analyze the distribution and source of multiple drug-resistant organisms in the Intensive Care Unit, ICU, to provide the basis for a more effective multi-drug-resistant bacterial control program. METHODS A retrospective investigation has been conducted on the MDRO infection of multi-drug resistant microorganisms (MDROs) in 8 ICUs in a large-scale tertiary class-A hospital from Jul. 2017 to Jun. 2018. According to the source, the MDROs in 8 ICUs were divided into 4 groups, namely, out-of-hospital infection (intra-hospital transfer, community acquisition) and in-hospital infection (in-hospital transfer, department acquisition) for analysis and study. RESULTS CRAB (64.8%) and CRE (20.09%) were the majority of the infected MDROs. MRSA (49.75%), CRAB (90.47%), CRPA (55.06%) and CRE (40.46%) were all higher than the data of 2017 national bacterial resistance monitoring network. The top three MDRO infection sites were lower respiratory tract infection (85.04%), bloodstream infection (4.69%) and surgical site infection (3.79%). The out-of-hospital and in-hospital infection rates of MDRO were 50.89% and 49.11%, respectively. The out-of-hospital infection rates of MRSA, CRAB, CRAB, CRPA and CRE were 47.36%, 54.04%, 58.97% and 38.33%, respectively. The source of MDRO infection obtained by the department was 43.86%, 40.69%, 37.18% and 52.78%, respectively. There was a significant difference between comprehensive ICU and specialized ICU wards in CRAB infection of community acquisition, hospital transfer, department acquisition and other sources (P<0.5). CONCLUSION More than half of the MDROs infections in the ICUs are transfered outside the hospital or community-acquired. We should strengthen the identification of the MDRO source and take more effective and precise infection prevention and control measures.