While producing medicinal plants is more economic in their natural habitat than in farms, their establishment problems and slow growth rate are the main constraints under the natural conditions. This study was conducted to investigate the possibility for seedling transplantation of thyme into the natural conditions, in order to investigate the effect of mycorrhiza inoculation on establishment of this species in Bahar Kish rangeland, Quchan. Seeds were planted in glasshouse in small trays for 45 days, after that, seedlings were inoculated with two mycorrhiza species, Glomus mosseae and Glomus intraradices. After one month growth, the inoculated seedlings were transplanted into the natural. A complete randomized Block design with 30 replication was used. The results showed that mycorrhiza colonization with G. mosseae was 92% and with G. intraradices was 68%. There was no significant effect of inoculation on seedling establishment at early season, but at the end of growth there was a negative effect by G. intraradices but a positive effect by G. mosseae. Symbiosis with G. mosseae increased dry matter of leaf, stem, total dry matter and height of the plants while with G. intraradices had reduced these traits or the effects were non-significant. In conclusion pot planting can be an efficient method for establishing T. vulgaris under natural habitats, G. mosseae can be a beneficial symbiant for establishment of T. vulgaris in Baharkish rangelands.