whitish colour. The average yield of essential oil of the samples is 0.23%. This investigation allows us to support that R. officinalis includes six chemotypes in eastern Algerian. The difference of these chemotypes variants is the concentration of Eucalyptol, campene, α-pinene and camphor. The antibacterial activity of the essential oils chemotypes was evaluated against nine bacteria (Enterobacter cloacae ATCC 13047, MRSA (Methicillin-resistant Staphylococcus aureus), Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, Pseudomonas syringae, Salmonella sp, Serratia liquefaciens ATCC 27592, Serratia marcescens ATCC 14756 and Shigella sp). The results showed that the essential oils have inhibited growth of bacterial strains. The essential oils chemotypes of Kherrata and the Bibans regions, generally exhibit antibacterial activity against the microorganisms’ tested. The camphor chemotype with three variants exhibits a moderate antibacterial activity.