This work was carried out in Experimental Farm of ( PPRI) during the season of 2012 and 2013.The aim of the study was to investigate the effect  of the inoculation of spearmint (Mentha viridis) plants with silicate dissolving bacterium (Microbacterium trichotecenolyticum) and or vesicular arbuscular mycorrhizal fungi (VAM) on the incidence of  root rot disease, plant  growth and volatile oil percentage. The obtained results are summarized as follows: in all cuts in the two seasons, treatment applied with pathogenic fungus alone  all plants died (control) . The  inoculation with silicate dissolving bacterium plus mycorrhizal fungi reduced  growth of tested fungus and at same time  spearmint plants were  significantly taller than other treatments in both seasons. The same trend was observed in the branching of spearmint plants except in the second cut of the first season, the differences between treatments were not significant. The combination between silicate dissolving bacterium and mycorrhizal fungi (VAM) significantly increased dry weight/ plant in the second cut at the first  season, also the highest  volatile oil percentage was achieved with this treatment. In addition GLC analysis revealed  that the highest percentage of carvone (the main component of the volatile oil) was produced with  that exact treatment.