The mechanical properties of wheat roots in mature were tested, and the curves o n stressstrain of wheat roots were measured by the electronic testing machine CMT2502. The microstructure of wheat roots was observed, and the SEM images of wheat roots were scanned by electron microscope. The relation between mechanica l properties and microstructure of wheat roots was analyzed, and mechanical mo del of wheat roots was established. The results showed that wheat root was a typ ical porous, nocontinuous, nohomogeneous and anisotropic composite material. Wheat roots had enough strength and good flexibility, and its carrying capacity depended on the thickness of thickwalled cells and the numbers of vascular bu ndles, as well as the connection form and strength of cells in roots. The streng th of primary root and secondary root were 2121～5725MPa a nd 308～1307MPa, respectively. 