The research aims to study the use of small business radio to promote the marketing of One Tumbon One Product (OTOP) entrepreneurs in Chanthaburi Provinces, through using 5 marketing tools such as advertising, public relations, marketing promotion, personal selling, and direct marketing. Small business radio is used as the main role to reach customers for making OTOP awareness and various services that can lead to developing marketing communications of OTOP entrepreneurs in the future. This research conducted quantitative methods by using a questionnaire about the use of small business radio to promote the marking of One Tambon One Product (OTOP) products in Chanthaburi Province. The sample was a group of 400 entrepreneurs from 10 districts of Chanthaburi Province.