According to the estimation of World Tourism Organization, it expects that the population of international tourists will up to 1.6 billions in 2020. With respect to international outbound travel, seniors are one of most frequently traveling segments because much available time owned after their retirement. The objective of this study is to propose a relationship model of country of origin image, destination image, travel service quality, and travel satisfaction. Path-analytic tests using data collected from 424 Taiwan's senior tourists suggest that destination image and travel service quality mediate the relationship between country of origin image and travel satisfaction and that destination image mediates that between country of origin image and travel satisfaction when Taiwan' senior tourists perceive low travel quality.