In regarding to sustainable tourism principles, a tourism island is assumed to provide tourists' needs in different aspects. "Thus, among the shorelines of the Island, public open spaces where contain a lot of tourists, should meet tourists' needs." It needs to be more focused as contemporary thinking of urban design, success of public open space addresses to meeting users' needs. In a tourism Island, users of these spaces majorly are tourists who would like to enjoy seashore. This study posits that tourists' needs in public open space are affected by numerous factors and specifically clarifies factor of travel motivation. It also takes Kish Island in south of Iran as the case where assumed to enhance the open spaces due to its current plans of tourism development. In this island as one of the main tourism destination of the country, tourists are the main users of public open spaces. The methodology of this study firstly involved reviewing the comprehensive literature of two fields including tourism islands and designing public open space and documenting the concepts. Then, the investigation drives an experimental study in Kish Island. It is content of a tourists' survey in the Island and a semi-structured interview with the experts who involved tourism planning or public open spaces developing in there. The results of the study clarified the factor of travel motivation should be considered to meet tourists' needs for public open space in Kish Island. It also shows relationship between tourists' needs in the spaces and indicates the groups of needs that are more or less affected by this factor. At the end, the study presents some suggestions for planning and designing these spaces that would certainly contribute towards improving the quality of them in the Island. These final recommendations help to enhance tourism development in Kish Island as well as can be generalized for other tourism destination with similar cultural and climatic characteristics.