The Purpose: of this study was to investigate the relationship among leisure involvement, flow experience, and Well-being in Sport of tennis participants. It was, moreover, meant to comprehend the different situation in the leisure involvement, the flow experience and Well-being in Sport for the tennis participants with background variables. Methods: The researcher used sampling and collected a total of 384 questionnaires. With the use of descriptive statistics, independent t-test, one-way ANOVA, and the multiple simultaneous regression analysis, the Results: were illustrated as follows. 1) The tennis participants of university had an upper level of cognitive on leisure involvement and Well-being in Sport, and had an medium level of cognitive on flow experience. 2) The length of playing tennis of participants had different perceptions on leisure involvement, flow experience, and Well-being in Sport. 3) The physical attractiveness, the centrality to lifestyle and self-expression for the leisure involvement can positively affect the flow experience and Well-being in Sport. As for the flow experience, our experiences, the clear goal and concentration can positively affect Well-being in Sport. It was Concluded: that the tennis participants of leisure involvement and flow experience to the positive effect Well-being in Sport and all closely related. Finally, it proposed a suggestion based on the results of the research in order to offer the references for the related units to promote the region of tennis.