Abstract: 【Objective】 To clarify the effect of Urtica laetevirens extracts on the growth and photosynthetic properties of wheat seedling. 【Methods】 The wheat cultivar Heimai 2 were used to analyze growth and photosynthetic characteristics in response to different treatments with Urtica laetevirens water extracts of roots, stems and leaves at concentrations of 0, 20, 40, 60, 80 and 100 g/L. 【Results】 The root aqueous extract promoted seedling length and dry weight of wheat seedling, the lower concentration of root extracts promoted root length, root dry weight and root-shoot ratio while high concentration of root extracts inhibitory effect.The stem and leaf extracts all inhibited the wheat seedling length, seedling dry weight, root length, root dry weight and root-crown ratio.With the increase of root extracts concentration, the Fv/Fm, Y(Ⅱ), Y(Ⅰ) and ETRⅠ value slightly then reach stability.The ETRⅡ and qP fluctuating changes NPQ and CEF decreased firstly then.Along with stem extracts concentration increase, the Fv/Fm, Y(Ⅱ), Y(Ⅰ), ETRⅠ, ETRⅡ and qP value were decreased significantly, while the NPQ and CEF were increased significantly.At concentrations of 80 g/L, the NPQ and CEF were 1.37 and 5.42 times that of the control, respectively.The leave extracts no significant between the treatment group and the control group the photosynthetic characteristics. 【Conclusion】 The comprehensive analysis showed that root extracts promote wheat seedling growth by improving the electron transmission rate and light energy conversion efficiency of PSⅠ slightly.However, the stem extracts cause a certain degree of damage to the photosynthetic system of wheat leaves, and inhibit the growth of wheat seedling.This damage be relieved by strongly stimulating cyclic electron transport and forming non photochemical quenching.The leaf extracts show inhibitory effect on wheat seedling growth, while it has no significantly difference on photosynthetic properties of wheat leaves.