On March 3，2020，an outbreak of African swine fever（ASF）in wild boars was reported in Shennongjia Forestry District of Hubei Province. In order to identify the occurrence and development of the outbreak，find out the causes，evaluate the status of contamination and spreading scope in wild boars and domestic pigs，and put forward targeted suggestions concerning ASF prevention and control，a field investigation was carried out by combination of emergency epidemiological investigation and laboratory test. It was found that the outbreak was caused by virus-contaminated pig products，and the epidemic occurred possibly in the autumn and winter of 2019 at the earliest. Then some suggestions were put forward，including further strengthening investigation and monitoring towards wild boars and domestic pigs，promoting the control during the process of boar breeding in forestry areas，strictly managing the processes of pig transportation，slaughtering and marketing，and carrying out publicity and education on civilized tourism and bio-safety disposal of kitchen residues to push the public to participate in scientific prevention and control of ASF.