Intercropping has become important in many parts of the world due to the optimal use of resources and increasing the quantitative and qualitative yield of medicinal and agricultural plants. To evaluate the effects of different intercropping patterns of black mustard and [d1] lavender on some morphological traits, essential oil content and the Land Equivalent Ratio [d2] (LER), an experiment was conducted based on a complete random block design [d3] in three replications on the research farm of Islamic Azad University, Yasooj Branch during 2017-2018. Different ratios of black mustard and lavender were intercropping treatments, these treatments included: 100% black mustard (black mustard sole crop), 75% black mustard + 25% lavender, 50% black mustard + 50% lavender, 25% black mustard + 75% lavender and 100% lavender (lavender sole crop). Study traits included root fresh weight, root dry weight, shoot fresh weight, shoot dry weight, number of branches, plant height, essential oil content and land equality [d4] ratio. The results showed that different intercropping patterns had a significant effect on all the studied traits. The highest content of essential oils and other mentioned traits in both plants were obtained by intercropping treatment (50% black mustard + 50%lavender). A positive regression relationship was observed between essential oil content and shoot dry matter in both black mustard and lavender plants. There was a positive and significant correlation among essential oil content and other traits in lavender. The Land Equality Ratio (LER) index in all intercropping treatments was more than one (1.38 and 1.84), indicating the superiority of the intercropping systems compared to the sole crop system. In total, intercropping of 50% black mustard + 50% lavender compared to sole crop is recommended due to the improvement of morphological traits and increasing its usefulness.