Coriander, Coriandrum sativum L, is an important medicinal plant belonging to Apiaceae family, which is grown in many parts of Turkey. In this study, essential oil and composition of 6 Turkish coriander cultivars (Gamze, Arslan, Erbaa, Pelmus, Kudret, Gürbüz) were examined in two different (Mardin and Tokat) ecologies. Essential oils were isolated with distillation method in maturated fruits and component composition was determined with gas chromatographyâmass spectrometry (GC-MS). Main component was linalool in all cultivar, and it was higher in the conditions of Mardin having a warmer climate in all the cultivars than that of Tokat with temperate climate. Contrary to linalool, α-pinene and neryl acetate contents of all cultivar were higher in Tokat.