The properties and tensile behaviors of polypropylene (PP) geogrids and geonets for reinforcement of soil structures are investigated. Mass per unit area of the geogrids and geonets was weighed using an electronic balance and aperture sizes of the geonets were exactly measured using a computer. Laboratory tests were performed using a small tensile machine capable of monitoring tensile force and displacement. Tensile failure behaviors were described, and tensile index properties such as tensile strength, maximum tensile strain, tensile forces corresponding to different strains in the geogrids and gronets were obtained. The characterization of these indexes is discussed.