To contribute to the valorization of Moroccan Rosem ary, we focused on one hand on the study and compar ison of the yields and chemical compositions of the essenti al oils of rosemary in four provenances (Wad Laou, AyounCharkiya, Sefrou and Agadir’s Gardens Jacky).O n the other hand, we evaluated their antimicrobial activities. Essential oils obtained by hydro-distillation of ro semary were analyzed by gas chromatography coupled to mass spectrometry. The average yields obtained and chemi cal composition vary according to the four provenan ces. The descriptive and comparative statistical study of ch emical composition of Rosemary from different regio ns by the principal component analysis method showed a good c lassification of Rosemary essential oils from diffe rent regions according to the chemical composition. The study of antibacterial activity of essential oils of Rosema ry in four regions showed an inhibitory power over all the str ains studied. This activity differs statistically f rom one region to another. Indeed, the highest antibacterial activity was observed for the Rosemary from Sefrou region a nd the lowest activity was observed for Rosemary from Agadir regi on and this for three strains used.