Unidirectional tension plastic geogrid is extruded by macromolecule polymers, and formed by longitudinal tension. This kind of geogrid is integrity with uniform distributed elliptical net structures. It has high tensile strength and tensile modulus. With this kind of structure, the geogrid provides an ideal interlock system for the soil. It has high unidirectional strength and endurance, and high lateral restraints for soil-rock mixtures. All property indexes of it are superior to geogrid without tension. It is an ideal reinforced material at present, such as reinforced earth structures in reinforced retraining wall, reinforced steep slope, bridged abutment and highway, railway and airport.