To contribute to the valorization of Moroccan Rosemary, we focused on one hand on the study and comparison of the yields and chemical compositions of the essential oils of rosemary in four provenances (Wad Laou, Ayoun Charkiya, Sefrou and Agadir’s Gardens Jacky).On the other hand, we evaluated their antimicrobial activities. Essential oils obtained by hydro-distillation of rosemary were analyzed by gas chromatography coupled to mass spectrometry. The average yields obtained and chemical composition vary according to the four provenances. The descriptive and comparative statistical study of chemical composition of Rosemary from different regions by the principal component analysis method showed a good classification of Rosemary essential oils from different regions according to the chemical composition. The study of antibacterial activity of essential oils of Rosemary in four regions showed an inhibitory power over all the strains studied. This activity differs statistically from one region to another. Indeed, the highest antibacterial activity was observed for the Rosemary from Sefrou region and the lowest activity was observed for Rosemary from Agadir region and this for three strains used.