Knowing the natural patterns and site demands of species is a good guide and can reveal the ecological characteristics of species to solve many problems in managing of forest lands, such as reforestation and rehabilitation of damaged areas. In this book, we analyzed the spatial patterns of three Quercus species (Quercus brantii, Q. infectoria and Q. libani) by univariate spatial analysis of trees and finding out the relationship between environmental characteristics and distribution of these studied oak species, at the less destroyed areas in the northern Zagros region of Iran.