Background: Mentha piperita and Thymus vulgaris are two important species of family Lamiaceae that abundantly used in pharmaceutical, food, cosmetic and hygienic industries.

Objective: Objectives in this study were the effect of different concentration of auxin and fungi Piriformospora indica and Sebacina vermifera on the growth and development of peppermint and thyme in vitro condition. 

Methodes: Two distinct experiments were conducted the first evaluate the effect of different auxin levels (IAA ، NAA ، IBA) on M. piperita and T. vulgaris growth, and the second examined the effect of two fungi Piriformospora indica and Sebacina vermifera on plant height, root length, shoots and root weight in in vitro in a completely randomized design.

Results: The first study suggested the most effective hormone dose for the M . piperita growth was 1mg per liter of IBA and in the T. vulgaris it was 1 mg per liter of IAA. Increasing of the hormone doses resulted in growth decrease. The second study evolved that growth of the plants inoculated with fungi increased significantly. The data indicated that the plants inoculated with S. vermifera were the highest of all and the plants inoculated with P. indica had the most weight. The nodes of M. piperita and numbers of shoots in T. vulgaris increased significantly.

Conclusion: These results indicate that the best hormone for tissue culture peppermint and thyme are 1mg per liter of IBA and IAA, respectively. Also using these fungi can increase grow and development of plants.