Background: Thymus kotschyanus (Lamiaceae) is a valuable plant species which mainly grow in mountainous regions. Different species of this plant have worldwide distribution especially in Mediterranean region. The plant is a woody, small, patchy, or perennial herb with a woody base. It is well known as a medicinal plant with energetic and antibacterial actions. The essence is especially used in drying industries, cosmetics and trade industries. Methods: To study genetical biodiversity of the T. kotschyanus and interaction of ecological conditions on the plant essence. The samples were collected from three elevation bands and the essence combination were analysed. Results: The results showed that essence content were between 0/95 - 1/87% and the yield is 1.23% and due to high content of essence is valuable in drugs industry. Generally, 37 different combinations were analysed by GC-MS. in elevation bands which showed Carvacrol (60.82- 82.05%) and Thymol (1.56-13.94%) are the most important substances in T. kotschyanus. Conclusion: This study showed that essence of this species has high content of Thymol and Carvacrol which are two medically important.