This paper intends to identify the factors determining the relative competitiveness of Taiwan's international tourism among a group of seven East Asian countries. Using data on visitors from the USA and Japan, the major message which emerged from this study is that there are sharp differences between factors affecting US visitors and Japanese visitors. Specifically, we found: (1) the decline of Taiwan's market share in Japan has been mainly due to appreciation of NT dollars and changing preferences, whereas they are not crucial factors in the US market; (2) qualitative supply-side factors indeed could have decisive influences on the market share. However, their effect is again origin-dependent. The open-door policy of China is the only important determinant of Taiwan's competitiveness in the US market, while it has no impact on the Japanese visitors.