This study identifies horse racing gamblers` characteristics by clusters of the involvement scale, and investigates the differences between these clusters on motivations to visit a race course, behaviors and attitudes, and socio-demographic characteristics. Authors took a on-site self-administered survey of 424 visitors to the horse racing place. Four distinctive clusters were found. The clusters revealed distinctive differences on motivations to visit a race course, behaviors and attitudes, and socio-demographic characteristics. Especially, members in cluster three were likely to be the most addicted to horse racing gambling, while those in cluster four were likely to be least addicted.