The present study aims to investigate the effect of Zen Buddhism philosophy and language's ideology in the forests and trees in the Sohrab Sepehri's. In some of poems, Sepehri has used the basic concepts of Zen Buddhism, including purity and the core of the relationship between vision and nature. The purpose of this paper is to study of the intellectual context and process of Zen Buddhism philosophy on the Sepehri's poems. In the search for this problem, the key concepts and categories of Zen Buddhist philosophy are first outlined and then analyzed in order to represent this attitude in the depiction of trees and forests as manifestations of nature in the selected poems of Sepehri. The present study was conducted using descriptive-analytic method. The current research showed that Sepehri used the forest and trees as symbolic myths in expressing Zen Buddhism's mystical thoughts in his poems. The forest and tree used as a symbol to describe the main components of Zen Buddhism, such as knowledge, escape from dichotomy and subconsciousness, in the "The Sound of The Water feet " and the «The Green Volume«. The present study showed the tree's position in Sepehri's poems has a high correlation with Zen Buddhism. The findings of the present study indicate the direct effect of Zen Buddhism's attitude on the Sepehri's poems particular emphasis on nature and tree.