Abstract: The use of geogrid is one of the major ways in the application of the roadway reinforcement, differential settlement control and the subgrade stability. This paper presents a case history of using the three-dimensional geogrid in the widening of South Segment of the Fourth Highway Circle Line in Huizhou City, Guangdong Province. Throughout the laboratory model static loading tests on the geogrid reinforced soils, the stress-strain characteristics in soils under the loading and the associated settlement are evaluated. The results indicate that, the slope stability of the roadway embankment is greatly improved. After the geogrid placement, higher composite strength is formed along the center of the roadway embankment. And the lower composite strength body is formed along the edge of the embankment. After the geogrid placement, higher settlement is observed at the centerline of the embankment, whereas, the edge of the embankment has larger settlement without the geogrid reinforcement.