This is an empirical research, which purpose aims to explore the relations between the motivation of participants of marine sport and its leisure constraint in Kenting area. The mode of sampling in this research is convenient sample that is not adopted randomly. We made totally 500 questionnaire and got 482 in reality after eliminating unqualified samples. On the basis of results of statistic analysis, we generalize several conclusions as follows: First, the majority of the participants of marine sport in Kenting area are male. Most of their age are less than 30. The level of their education are mainly college level. Their other attributes are: single, no child, monthly income less than 10000 NT dollars, and weekly exercising time less than three hours. Second, their participant motivation is mostly for the purpose of “self-fulfillment”, and their last concern is “skill development.” Among these participants, there is remarkable difference of motivation between each of them, which is shown in several background variables, such as: gender, age, level of education, marriage status, parental status, monthly income, and weekly exercising time. Their occupation does not manifest remarkable difference on the motivation. Third, with regard to leisure constraint, the main element is “environment and economy”, and the less concern of participants is “self-limitation.” The interaction between background variables and leisure constraint is greatly influenced by the variables of gender, level of education and weekly exercising time. The factors of age, occupation, marriage status, parental status and monthly exercising time are notinfluential. Forth, according to the result of correlation analysis between five factors of participant motivation and four factors of leisure constraint, it can be concluded that people who have higher participant motivation get less leisure constraint.