In order to examine the allopathic effects of saffron organs on the growth and germination of two species of Hordeum murinum L. and Descurainia sophia L. weeds, an experiment was done in the school of agriculture of the University of Torbat Haydarieh, Iran. The experiment was done as factorial in a completely randomized design with four replications with different levels of organs (leaf, corm and a combination of leaf and corm) and extract concentration (zero, 1, 2.5, 5, 10 and 20 percent). The results indicated that saffron extract has negative effects on growth and germination parameters such as the length and weight of the root, stem and seedlings, the speed of germination, the percentage of germination, the seed vigor index and the number of normal seeds in both species of weeds. The highest germination rate was shown by Hordeum murinum (10.48) that was obtained in the 2.5 percent application in the leaf and corm extractions. In addition, in this weed the highest seed vigor index (21.75) was seen in the application of 2.5 percent of leaf extraction and the lowest seed vigor index was obtained (10.75) in the 20 percent application of leaf and corm extractions. In the D. sophia L. weed the highest seed vigor index was 21 and the number of normal seeds was 15.75, respectively, in the one percent concentration of leaf and corm and the 2.5 percent concentration in the corm extraction and its lowest value was seen in the 20 percent of leaf and corm extraction. The application of leaf and corm combination extraction in comparison with leaf and root separately, significantly lead to a reduction of the germination traits. On the whole, its seems that using the saffron extracts in the concentrations of 10 and 20 percent significantly affect the growth and development of Hordeum murinum and Descurainia sophia weeds negatively in the germination stage