On May 15，2020，it was reported that，by Qingyuan Animal Disease Prevention and Control Center of Fushun City，some goats suffered from an acute disease in a household in Qingyuan County，with a high mortality rate. On May 16，it was diagnosed to be a suspected outbreak of peste des petits ruminants（PPR）through field clinical diagnosis by the municipal expert team and reexamination by provincial laboratory，and subsequently confirmed as PPR through detection by National Reference Laboratory for PPR. On May 18，the outbreak was announced by the Ministry of Agriculture and Rural Affairs. In order to trace all possible sources of the outbreak，analyze the risk of spreading and to scientifically guide relevant disposal，an epidemiological investigation was carried out. Results of field investigation showed that，the attack rate of the outbreak was 72.7%（136/187）and the fatality rate was 55.9%（76/136）. It was indicated through traceability investigation that，the outbreak was likely caused by the virus carried by sheep dealers and the vehicles as well as purchased sheep without inspection and quarantine，especially，the internal risk factor was that some newborn or purchased lambs were not vaccinated with PPR vaccines in time. Through follow-up investigation，it was shown that the outbreak was limited to the household with a low risk of spreading. Therefore，comprehensive bio-security measures should be strengthened within farms，with the priority to control the movement of relevant personnel，transportation vehicles and tools，and to vaccinate lambs with relevant vaccines，so as to reduce the risk of any outbreak.