Consideration of tree suitability is critical when selecting species for afforestation.However,tree suitability can not be clearly defined.At the same site, some tree species grow well in scattered plantings,but do not grow well in pure stands.In reality, some species may be characteristically suitable for the site but not be suitable for forestation.The authors advance here that tree suitability including for forestation should be emphasised. The tree suitability concept has been based on aims to establish woodlands of considerable area using specific forest species and structure in areas adapted to woodlands.A ccording as the principle of vegetation succession,bioecology,synecology and niche theory,it is necessary to select those species that can form stands as chief species.Such stands should be associated with companion plants to establish rational community structure.