The aim of this study was to assess the fatty acid compositions, tocopherol contents and some biochemical properties of 'Ayvalik', 'Memecik', and 'Topakasi' olive cultivars' fruits grown in Mediterrenean region of Turkey, Sutculer/Isparta. According to mean values the highest value of oleic acid (73.88 %), which is the most dominant acid in olive fruit, was found in Memecik. The highest value for alpha tocopherol content was obtained from Topakasi (213.63 %) whereas the highest values for beta, gamma and delta tocopherol contenst were obtained from Memecik (2.46, 4.19 and 0.31 % respectively). Memecik had the highest values for chlorophyll (0.47), carotenoid (0.31) and pheophytin a (2.29) contents according to mean values. According to the knowledge obtained from the research, the fatty acid composition and the quality characteristics of the olive oil are mainly depended on the growing conditions, harvest period and the oil extraction methods. In the study, it is concluded that 2nd harvest period for Memecik, 2nd and 3rd harvest periods for Ayvalik and Topakasi would be more suitable under the Isparta, Sutculer growing conditions for high-quality olive oil. This research is the first detailed research on olive in the research area and it is considered that it will be the basis to future scientific studies.