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Allelopathy is the beneficial or detrimental effects of  plants on other plants which due to direct and indirect secretion of chemical compounds from live or dead plants. In this research, to evaluate the allelopathic potential of Atriplex canescens on Medicago scutellata as a non- native plant introduced for range management projects of the Eastern Golestan province was investigated. Standard phytochemical tests for qualitative analysis of allelochemicals such as viz. Saponins, Terpenoides and Anthocyanins were carried out in the laboratory of Hydroecology at the GonbadKvous University. The allelopathic potential of different concentrations of aqueous extract (Control, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100 %) of the Atriplex canescens at the flowering stage on germination characteristics such as root length, shoot length, seedling growth, germination percent, speed of germination, vigor index, physiological (chlorophyll a, b and total) and biochemical (total phenols) of Medicago scutelata seedling were analyzed to form completely randomized design with three replications. In qualitative analysis, all allelochemicals under study except Anthocyanins were observed. The results of this study showed that the effect of different concentrations of aqueous extracts of A. canescens on germination characteristics, physiological and biochemical of M. scutellata at the level of 0.01 were significant. Analysis of data at different concentrations on germination and physiological characteristics indicated significant decreasing trend as compared to control, while the total phenols increased. At concentrations higher than 50%, 100% inhibition of germination and physiological characteristics were observed. This growth inhibition effect was probably due to increase of  allelochemical concentrations like Saponins, terpenoids and total phenols in higher concentrations which acted in combination and their affection at cellular level or organ.