In Japan, since the period of high economic growth, lots of remote island have been connected with the mainland by bridges. Those enterprises were based upon both the negative views that islands must be underdeveloped area and so sustainable life systems have not yet been constructed in many of the Japanese islands. And consequently, the number of bridged islands have amounted to 118 up to the present in this country. However, though reliable transportation routes to the mainland have made, diversity of life-spaces in these islands have not yet come into existence. Indeed, the function of community in the bridged islands has been weakened so much. This paper aims to examine the actual condition of the bridged island, Kouri-jima, situated in the northern part of the sea near Okinawa-jima, where the fixed link to the mainland have completed in 2005, and to consider how the bridge mean to the island societies. The islanders in Kouri-jima evaluate the change of their everyday lives after the bridge has laid, from two contrastive viewpoints. They positively recognize that they owe much the certainty of the traffic route to the mainland and the improvement of their medical care system to the bridge. In fact, the new route has brought convenience and flexibility to some of the islanders. However, on the whole those merits were restricted to a narrow range of their everyday lives, such as shopping and an emergent patient. Additionally, it has brought the increase of living costs, over-dependence on the mainland and the deterioration of environment due to the rapid increase of tourists to the island. The islanders, on the contrary, feel most seriously the decline of the function of community. They said that the bridge caused the everyday lives of inhabitants mental and physical and economical disadvantages, at each level of individual, family and community. Because of both “a certainty of the traffic route” and “functional decline of community”, the “lifestyle of the island”, that essentially depends on the surrounding sea, has changed so much. It must be the weakening of social relation between the islanders, which has been the basis of the traditional island society. As a result, both the narrowed range of the activities and the broken community have dissipated the life-spaces of the island. The condition of island, which the original island space has been lost and become chaotic, symbolizes modern island society that has integrated to the mainland by bridges.