Olive oil is an important component of the diet of the countries surrounding the Mediterranean Sea. The objective of this book is to show the interest of olive oil in human nutrition and to characterize olive oils from six Algerian cultivars by determining their fatty acid compositions using gas chromatography of methyl esters obtained by transesterification of triacylglycerolsand to analyze the bioactive compounds on the health of the unsaponifiable fraction of three olive oils from three cultivars of eastern Algeria. All the values of fatty acid compositions are in compliance with the regulation of the international Olive Oil Council and Codex Alimentarius. The "morphogramme" is designed as a radical representation of each fatty acid using an Excel spreadsheet , and each axis represents the change in the variable with respect to the mean. The "morphotypes" are real fingerprints of different oil cultivars. This mode of representation is particularly effective for the rapid visual identification of characteristics of olive oils. Analysis of bioactive compounds of tree cultivar, revealed presence of some minor constituents, including, the predominance of beta Sitosterol.