Ethiopia had practiced Judaism before Christianity. This church is unique in the continent of Africa and glob in holding judo-Christian sect. In the church tradition forests are considered as shelter of the earth crust which provides enormous scenery to the world. Most of the Ethiopian Orthodox Tewahido Church and monasteries are built on hills, mountains and high places which are covered with densely forests. This practice and tradition was comes from Eden, the place had all the best and choicest trees and plant, God a tender Father, provide not only for Adam’s needs, but also his pleasure. The church on the earth signifies the new heaven, the holy city, New Jerusalem, coming down from God out of heaven, prepared as a bride adorned for her husband, Adam. Therefore, gardening was the first kind of employment on record in which man was engaged. Though trees and plants produced the necessary flower and fruits by the will of God, dressing and keeping are necessary to maintain in their perfection. The greenery in Eden is the underlying principles on which Ethiopian Orthodox Tewahido Church dwell to conserve nature. Existing literatures on the nature conservation role of Ethiopian Orthodox Tewahido Church is not the detail. Therefore, published articles and Holy Scriptures were reviewed and presented in a more coherent manner. The main objective of the paper is to explore past and present work on sacred grove role in general, Ethiopian Orthodox Tewahido Church in particular in mountain ecology management and biodiversity conservation. The result shows that unreplaceable role of Ethiopian Orthodox Tewahido Church in conserving forest and mountain biodiversity in Ethiopia by indicating large scale forests and ecosystem is currently under the custodianship of Ethiopian Orthodox Tewahido church and its role on carbon emission reduction in the changing world. Therefore, recognizing the indigenous knowledge in biodiversity and mountain conservation and customizing the best practice from it would help global efforts on remnant resource conservation. It is a win-win scenario for diversity management and mountain conservation policy formulation effort too.