Present study reports a comparative screening of three ecotypes of Ziziphora tenuior L., sampled from three region with different elevation in middle and northeastern Turkey, based on their essential oil composition, total phenolic content and antioxidant capacities. Z. tenuior ecotypes showed twenty compounds, representing 89.18-91.44% of the essential oil (EOs) identified by GC-MS. The major components of EOs in ecotypes were pulegone (37.23-49.12%), and followed by 1,8-Cineole (2.26-7.78%), limonene (4.20-5.44%), beta-Caryophyllene (3.88-5.11%) and thymol (2.68-4.11%), respectively. Ecotypes showed variable pulegone content and it was increased with elevation increase. The total phenolic contents varied among ecotypes ranged from 21.13 to 27.50 mg of gallic acid equivalent/g EOs. Antioxidant capacity was determined in vitro using DPPH radical-scavenging and FRAP (Ferric reducing power) assays and expressed as concentration of each extract required to inhibit radical by 50% (IC50 and EC50) values that ranged from 0.80 to 0.97 mg/ml in DPPH and 0.42 to 0.55 mg/ml in FRAP assays, respectively. Our results indicated that antioxidant capacity changed among ecotypes. Taking into account the essential oil content, it seems that to select ecotype was the most appropriate to obtain more pulegone for this plant from its wild habitat.