" In present era of globalization and modernization there is growing concern of indigenous knowledge and the resource management especially in the case of CPR, indigenous people and associated development activities. On the name of developmental projects many irreversible negative impacts has been identified on the environment like species extinction, destruction of natural resources, loss of traditional knowledge of the indigenous tribal people etc. Particularly the Indigenous Peoples are becoming increasingly vulnerable to exploitation on the name of development activities, where traditional wisdom and knowledge and natural resources have been expropriated for business interests. These are serious concern for the survival of present world communities." Recently Ecotourism has emerged as development tool, which aims to protect the natural environment and cultural diversity by attracting the ecotourist and generating the source of revenue for the local people without harming the nature. This has been supported by various global processes. These processes has agreed to resolve the crucial problems related to indigenous people, their ownership rights and conservation of natural resources by clearer understanding and recognition of the strong ethical and spiritual dimensions and survival spirit of Indigenous Peoples in the changing world where Ecotourism can prove supportive as it works at local scale and incorporates land-scape and people-scape in particular." The success of ecotourism activities at an operational level depends upon an array of factors owing to its nature. Ecotourism can be the thin edge of a wedge, which opens the door to mass tourism and has every possible scope to be used by general tourism practitioners as brand name. This very concept could be misused to fulfill their economic motives. Scope of implementing certification concept is strong in the process of sustainable development of Ecotourism. Therefore, there is need to develop an applied tool to measure threshold of tourism impacts and change in socio-economic and environmental status of the site through Criteria and Indicator (C & I), under the framework of sustainability. The development of C&I is not an end in itself, it is a continuous process which encompasses the societies responsibility for sustainable livelihood generation through community based Ecotourism without environmental degradation and erosion of cultural values." Implementing C & I in the field, in particular requires community participation in CPRs management to gain the understanding and support of the local people, so that they can respect and contribute to conservation of the natural resources to keep its environmental value intact. Under this purview, C & I has been developed with participation of the local people at village level by using PRA techniques and organizing field level workshops. The research finding has been used to test the ecotourism performance at two study areas in Sikkim, India. Under this study, various results have been achieved in social, economic and ecological dimensions. In one of the study area the environmental and cultural values are intact because the indigenous people have developed a sense of belongingness, environmental awareness and worked collectively to maintain nature. They have developed local level institutions, which keeps an eye on the process of ecotourism development and share their experiences to make others aware. While in the other site, the local community involvement is negligible and could be linked with globalization. The results shows that due to economic motive and less involvement of local community in the process of …