Land is the premise and guarantee of island tourism development, ocean exploration and development of space new land, so the island tourism interactive development has become one of the hot issues in academic circles. In recent years, with the development of marine economy, experts and scholars in various fields pay more and more attention to the sustainable development of marine economy. So island tourism has become an indispensable part. “land-island tourism integration” not only promotes the objective needs of the island's economic development, but also realizes the actual requirements of the development concept about “innovation, coordination, green, open, and sharing”. As is well known, with the economic globalization and regional economic integration becoming deeper, the economic relation and cooperation between regions also become stronger. Every region can not obtain any development in the state of isolation, except for the development of island tourism , so island tourism needs the powerful economic support of the country. Taking Changshan Islands and the 14 cities in Liaoning Province as an example, the author analyzed the relationship of tourism spatial mutual effects between islands and cities in mainland . These relationships have three basic conditions: tourism function complementary, the transferability of tourism elements and the opportunity to intervene. Using the spatial interaction intensity, the economic connection degree and the economic membership degree and other quantitative methods, the author drew the interaction and economic membership degree of different characteristics between the 14 cities, Changshan Islands and the 14 cities and Changshan islands in Liaoning Province. In order to clarify the relationship between the three in tourism development, this article gave some advice for their different relationship. The author suggested that fistly Changshan Islands and 14 cities in Liaoning Province should be implemented land-island Interaction and mutual benefit; secondly, the 14 cities in Liaoning Province need to cooperating with tourism industry each other, formed Point-Line-Surface comprehensive development; thirdly, the Changshan Islands must establish system to combinated and layer characteristic development of each island. The author summarized this part and gave opinions: 1) the interaction of tourism space, with the increase of the distance between the tourism economic link degree, the 14 cities in Liaoning Province and Changshan Islands showed negative correlation; 2) the greater between the city tourism economic link degree and the stronger interaction of tourism space, mutual and island tourism spatial effect more frequently; 3) according to the travel breaking point formula, Shenyang, Dalian and Dandong are the potential resources of tourism in Changshan islands. As is shown above, the author thought that the island tourist development need depending on land economical development, playing with land economy power and radiation force, and achieving mainland-island tourism integration.