「淨土」可視為大乘菩薩精神的具體展現。比對淨土經典的內容，雖然也存在著許多對土地、樹、水池等淨土環境的描述，但是這些環境的特徵乃朝向超現實的理想發展，具有種種宗教的象徵意義，以形成相對於「凡俗空間」的「神聖空間」。這樣的「神聖空間」，事實上是以「眾生的修行」（佛法永住）作為最主要的考量，並不著眼在於自然環境的改善。因此，淨土思想如何成為環境哲學的思想資源便成為一個嚴重的問題。 本文考察「心淨則國土淨」的種種涵義，認為其關鍵乃在「眾生淨」。佛土淨（果）是眾生淨（因）的行果，淨土必須藉由眾生的心淨才可示現，其重點在於眾生的「心」而非外境的國土，因此要建立佛教生態學必須有個「土地倫理的轉向」。 本文從穢土成佛的悲願來說明土地倫理轉向的必要性。眾生皆立足於土地，關注土地、發揚土地倫理，雖不是佛教原本就有的教義，然依穢土成佛的精神，發願為改善日趨惡濁的生態浩劫而努力，應是人間菩薩精進法也是契理契機的慈悲行。 然當代人間淨土行者，所重在「淨」，關於「土」的意涵再詮釋與建構，往往被忽略與輕視，以致於土地倫理在制度化的實踐中並未有適當的地位。因此，本文提議對「心淨則國土淨」給予生態學的詮釋，嘗試提出佛教土地倫理的實踐原則。

“Pure Land” is made out of the compassion of the Mahayana Bodhisattvas. In the Mahayana sutras, the land, trees, and pond in the “Pure Lands,” are described in light of their religious implications rather than the environmental significance as they are portrayed as forming a “sacred space” in contrast to the “mundane space” and they can assist the beings' religious practices residing in the Pure Lands. Therefore, for scholars of the environmental philosophy, how to draw on these thoughts for the discussion of environmental philosophy has become an issue. In this paper, I would like to analyze the possible implications of the idea “when one's mind is pure, then the land will be pure.” I would like especially to single out the idea of “the purification of mind.” In the Pure Land sutras, the purity of the land is the result and the purity of one's mind is cause. The focal point in this statement is “people's mind” but not “the land.” Therefore, the possible connection of this idea with Buddhist ecology will have to be prinpointed from a specific perspective. I will point out the clues that show us this connection lies in the idea of “attaining Buddhahood in polluted lands.” According to this theory, as a way to move ahead in one's Boddhisattva path, one has to be committed to improve the world in which he lives in to attain Buddhahood. Although this interpretation is an extension of the Buddhist philosophy and not expounded in the sutra, but the necessity of attaining Buddhahood in the polluted land, but not the pure land, demonstrates the importance of the concern over the environment that one lives in the Buddhist philosophy. Recent scholars working on Engaged Buddhism or “Buddhism in the Human Realm” usually give more attention on the aspect of “Purity” instead of the “Land.” In this paper, I will propose a Buddhist ecological interpretation of the idea “when one's mind is pure, then the land will be pure as well” and try to formulate some basic principles in putting this ideal into practice.