Corynebacterium stationis is a facultative anaerobic gram-positive bacteria. It is an opportunistic pathogen that is one of more than 42 corynebacterium species and subspecies found in humans, the majority of which have been linked to opportunistic illness. Human excrement, blood, and sea water are commonly used to isolate it. Mastitis in cattle is caused by the bacteria c. stationis and is characterized by inflammation of the mammary gland.. Milk from the infected cows is contaminated with bacteria, making it unsafe for human consumption and causing bacterial diseases in humans. .In this study , we investigated the antimicrobial activity of some essential plant oils  against c. stationis bacteria isolated from human feces. One bacterial isolate was identified biochemically then characterized by 16s rRNA genotyping and was designated as Corynebacterium stationis strain M.S . Antibiotic susceptibility  test showed  resistance of  c. stationis M.S to  three  antibiotic (Erythromycin ,Clindamycin and Azithromycin). By using thirteen Egyptian essential plant oils .we invitro  investigated and indicated the efficacy of black seed oil and rosemary oil against c. stationis M.S  with inhibition zone of 18.00 ±1.3 mm. The Minimum inhibitory (MICs) and Minimum bactericidal concentrations (MBCs) of black seed and rosemary oils  against c.  stationis M.S were found to be 19.5 mg/L and 39 mg/L respectively . Killing time of c.  stationis M.s  upon growing with 200 mg/L of black seed and rosemary were after 6 and 7 hours, respectively.