Abstarct: Soil contamination with petroleum compounds was observed since the petroleum exploration in Iran have been started in the lastcentury,. Theaccumulation of these compounds in the environment threaten the health of soil and water resources. This research was conducted with the purpose of reaching to an efficient approach for the remediation of soils polluted with petroleum compounds. In this research the effect of biochir, mycorrhizae fungi and combination of biochar with mycorrhizae were studied. The analyses showed that highest yield of Trifolium plant was in mycorrhizae treatment. Total hydrocarbons decreased until 47.5% in control treament ( only plant) and until 75% at the presence of mycorrhizae symbiosis. The highest yield of .... was observed in biochar+ mycorrhizae ( until 75%) and the lowest in control (35%). Also, the study of 16 compounds of alkanes showed that the plant with all of the mentioned compounds had the highest decomposition rate. And the control sample without plant showed the least amount of decomposition.