Reintroduction is one of the important methods in wildlife conservation in order to initiate a viable free ranging population, especially in the endangered species, which needs the co-operation includes ecologists, biologists, behaviorists, veterinarians and co-ordinators who distribute the knowledge to public. Despite reintroduction may raise not only questions regarding to animals survival, transmissible diseases and genetic diversity, but also impacts to inhabitants, ecology, food chain and community. First elephant reintroduction occurred in January 1997 at Doi Pha Muang wildlife sanctuary in order to study the possibility of bringing the domestic elephants back to the natural habitat to conserve the elephants from extinction. Presently, the project included 64 elephants, of which 29 were released to Doi Pha Muang wildlife sanctuary (northern Thailand), 21 elephants to Sublanka wildlife sanctuary (central Thailand), 5 elephants to Phuphan national park (north east Thailand), and 9 elephants are under the behavioral adaptation process. These elephants were categorized in 4 groups; a) adult female b) cow-calf c) male d) juvenile. Seven elephants in Doi Pha Muang wildlife sanctuary were selected for behavioral and monitoring study. The methods included health monitoring, individual and interaction behavioral changes and impacts to community and ecology. The results showed that the elephants could survive in the forest, and the natural habitats in Thailand were proper for elephants in group a) and b), while those in group c) and d) could not be concluded due to the number of elephants under long monitoring. © 2012 by Nova Science Publishers, Inc. All rights reserved.