A geogrid using fiber-reinforced polymeric strips and its producing method are disclosed. The geogrid of a lattice shape includes plural longitudinal fiber-reinforced polymeric strips longitudinally arranged in parallel at regular intervals and formed by reinforcing fiber in a thermoplastic polymer resin, and plural lateral fiber-reinforced polymer strip laterally arranged in parallel at regular intervals and formed by reinforcing fiber in a thermoplastic polymer resin. Each longitudinal fiber-reinforced polymer strip has at lease one first contact point crossed with the lateral fiber-reinforced polymer strip on the upper surface and at least one second contact point crossed with the lateral fiber-reinforced polymer strips on the lower surface. The contact points are fixed by welding the longitudinal and lateral fiber-reinforced polymer strips. The geogrid is excellent in installation capacity, frictional feature and shape stabilisation and shows high tensile strength and low tensile strain and low creep deformation.