This paper aims to analyze the concept of ecological religion of Toba Batak in an attempt to revitalize the local religious wisdoms in their relationship with natural environment. There are three main major questions: first, what is the ecological religion concept of Batak Toba in perceiving and relating to their environment and how do they imply that concept? Second, how do their ecological religion practices in maintaining their environment? Third, what are their problems (internal and external)? This the analysis was based on field research conducted during a certain period in a determined area, Sianjur Mula-mula, Samosir District, North Sumatera Province. Determination of the area was done by looking at the historical aspects of the area and its meaning for the people who live there. By doing ethnographic research, the data obtained by directly interview and live among the informants. However, redefinition of religion and ecology will be the first step in this paper. With the data, how the concept of Toba Batak religion in relationship with their environment in the midst of changing times today, will be shown. As a culture, Toba Batak community has experienced some transformations in many aspects such as religions, economic, culture, daily life, etc. This transformation emerged many problems. In this thesis, these problems will be seen as challenges as the informants said. Redefinition of religion and ecology will bring the reader to the new paradigm of this indigenous religion. World religionâ ï¿ ½ï¿ ½s paradigm is not good and the best to understand indigenous religion. It will make them to be unproductive forward to ecological system. Their perspective on ecology is very different. They perceive their environment as subject, person, and one of their families. So, religion for them is how they related to the other persons people. Ecological subject is their family. In this sense, ecological religion of Toba Batak is an inter-subjective relationship between human and the-other-than-human-person. For them, tondi is the essence of relationship. The other-than-human-persons were perceived as person because they have tondi. In addition, all of persons have responsibility, right, and intention to share and give because they have tondi. All of their activities have one purpose: that is keep the balance of cosmos. Based on that new paradigm, we will see how Toba Batak people, especially Sianjur Mula-mula society imply their worldview in practicing their ecological religion. They perceived padi (rice) as inang (mother) because padi has a great tondi based on her rules in human life. This familial relationship invited them to give a huge respect to the rice. Their respect was is come up through their activities, behavior, and communication with padi and how they touch the padi. There are many taboos in their relation to cover and protect it. Beside of padi, there are also the other non-human persons. For instance, land as they called Boras pati ni tano, is very respected in all their activities. The will make ritual when they want to build house, engage in farming. For them, land is a person who has a great power in their lives. Boras pati ni tano has given life, fertility and prosperity for human. At In another word, Boras pati is the tondi of the land. Ecological religion of Toba Batak in Sianjur Mula-mula country is very important. This concept can be explored to keep the sustainability of Toba Lake and the environment surrounds them. The problems were emerged in the end of chapter to realize us on them. They are challenges that want to teach us to keep the earth.