Abstract: Tourist spatial structure is a complicated topic. In this paper, based on the study progress in China and foreign countries, some "spatial models of tourist system" are proposed by single factors, such as behavior, tourist zoning, tourist attractions and tourist flow. Then taking Xi'an as an example, Tourist Destination District is defined and analyzed. By using "One-day Tour Circle", the range of TDD in Xi'an is proposed, including the district with 250 km as a radius (2.5h traffic-time distance). Based on zoning of TDD in Xi'an, the distribution of high-grade tourist spots (up to 3A) is analyzed. That agglomeration of high-grade tourist spots is convenient to develop tourist attraction cluster, which is concentrated on Xi'an urban built-up area and its adjacent districts. By the analysis of Lorenz curve, serious disequilibrium of different tourist routes in TDD of Xi'an is concluded, which indicates that different routes has different intensities of utilization, agglomeration of visitors in the eastern routes has strengthened the capacity of destinations such as army ruffian and Huaqingchi spring. Main conclusions in this paper include: two components are very important to the sustainable development of regional tourism, which are tour nodes and travel paths respectively. Scale, spatial distribution and tourist flow of tourism industry is strongly influenced by tourist spatial components, especially spots and routes. With the integration of tourist market, redisplay of tourist routes and connection with strong and weak tourist spots, the best tourist products can be brought out. Improvement of competition of tourist products is the key of TDD.