Abstract: In the construction of approach channels in a plain area, a lot of clayey soils are excavated. If the excavated clayey soils are filled into woven bags, they can be used to build retaining walls. The principle of treating clayey soils with soilbags is studied through laboratory tests. A 100-m testing retaining wall constructed with soilbags filled with clayey soils was designed and applied in the Yanglintang channel project. The behaviors of the retaining wall are studied through the field monitoring of the lateral deformation, lateral pressures and surface settlements of the retaining wall. The test results show that the soilbags can benefit the consolidation of clayey soils in the bags and increase their strength. The monitored maximum lateral deformation and the surface settlement of the retaining wall are 29.42 and 19.2 cm respectively after 7 months of the completion, hence quite stable. The lateral earth pressure on the front retaining structure is positively reduced owing to the interlayer friction of soilbags. The cost of the retaining wall constructed with soilbags has an obvious advantage over that of the conventional gravity concrete retaining wall.