Abstract: This study presents the study on the ethnography of the communities at Thai-Laos boundary. Its aim is to examine the socio-economic change of the communities located along the Mekong river, the border between Thailand and Lao PDR. The concept of space and boundary is employed as the key method to conduct this study. This research desires to indicate that the Luang space in the Thai-Laos boundary is not only a physical space where people can do fishing but as the status of the socio-economic space. It is a flexible area in Thai-Lao bordering area as well as a contested space caused by governmental power, upholders and local communities; this disputed borderline was originated from the state of being a modern nation state during the French colonization of Laos. Yet the people living on both sides of the river do not surrender to government power. Conversely, they have undergone an operation to reinforce their community power to overlap the political power.