In order to investigate the incidence of canine adenovirus(CAV) infection, sera from a total of 109 unvaccinated tigers from 6 districts of China were examined for antibodies to canine adenovirus typeⅠ(CAV-1) and canine adenovirus typeⅡ(CAV-2) by hemagglutination inhibition(HI) test. Antibodies to CAV-1 and CAV-2 were prevalent with positivity rates of 28.4% and 10.1%, respectively. The results suggested that tigers can be infected by CAV.