Allelopathic compounds display an important role in biodiversity, stability and ability of ecosystem production. An experiment was conducted to investigate the allelopathic effect of six species, Cordia myxa, Melia indica, Delonix regai, Terminalia catappa, Eucalyptus camadulensis, Ficus religiosa on germination and seedling growth of Calendula officinalis. An experiment was performed in a completely randomized design with three replications in the lab of the horticultural Hormozgan university during 2014. A completely randomized design with three replications was carried out in the laboratory. Results indicated that the percentage of germination, seed germination rate, plumule and radicle length, and seed vigor of Calendula officinalis significantly reduced under aqueous extract of all species. But, there was no significant difference between dry weights. Delonix regia extract ceased the seed germinates in both concentrations. After that Melia indica extract had a highly significant inhibitory effect on seed germination, plumule and radicle length when compared to control. The results of this experiment also showed that the inhibitory effects of Cordia myxa and Terminalia catappa were lower in compared to other species. Between two concentrations, 100% concentration has a more inhibitory effect. The results of the present study revealed that inhibition of germination and growth parameters of Calendula officinalis showed variation according to the different plants. Cultivation of Calendula officinalis with Melia indica, Delonix regia species don’t suggest in the landscape.