The aqueous extracts of Tamarix spp.were prepared by three plant tissue collected in the Lower Reaches of Tarim River,and Salsola collina Pall.,one kind of the local perennial herb,was taken as the test plant.The indoor petri dish method was utilized to analyze the allelopathy of Tamarix spp.aqueous extracts on the seed germination and seedling growth of Salsola collina Pall.The result show that:(1)The Tamarix spp.extracts of stem and root both significantly restricted the seed germination of S.collina.The differences of germination rate,germination index,and vitality index of S.collina all reach the significant level in between the stem treatment groups of 0.08～0.20 g/mL and control group.The germination rate decreases by 84.78%,89.12%,76.09%,and 67.39%,respectively.The allelopathy of toot extracts on the seed vitality index of S.collina is more significant.Extreme significance exists between the treatment groups of 0.12 g/mL or 0.16 g/mL and the control group with the response indexes of -0.960 and -0.930.(2)The stem and root extracts of Tamarix spp.presented significant allelopathy on the seedling length and fresh weight of S.collina,respectively.The seedling length and fresh weight both increased by 61.49% and 52.63%,respectively,in the treatment groups of 0.08 g/mL.The extracts of other concentrations all have the restricted impacts.(3)The comprehensive allelopathy of leaf extracts of Tamarix spp.presents the trend of W,the stem extracts have stronger comprehensive allelopathy in higher concentrations,the root extracts have the strongest comprehensive allelopathy in the concentration of 0.12 g/mL (RI=-0.749) and the weakest in the concentration of 0.08 g/mL (RI=-0.389).