Denaian thyme is scientifically named as Thymus daenensis Celak., which belongs to Lamiaceae family. The Mediterranean region can be described as the center of the genus. Thyme is one of most important medicinal plants that was used in pharmaceutical, food, cosmetics and hygienic industries in most of developed countries. Thymus species have strong antibacterial, antifungal, antiviral, antiparasitic, spasmolytic and antioxidant activities. Breeding programmes need to identify the best land races as base population. Existence sufficient genetic diversity also is important in selection the superior individual amongst. In the present study, the dried aerial parts of plant analyzed by using GC/MS. The nineteen compounds were identified in dried aerial parts. The major components were γ-Terpinene (42.35%), Thymol (14.18%), α-Thujene (10.74%), linalool (5.42%), Borneol (2.48%), α-Terpine (1.54%) and Carvacrol (1.07%). This land race was collected from Isfahan province having high amount of γ-Terpinene and Thymol so is promising population for breeding programmes via selection to improve medicinal value of this important medicinal plant.