Abstract: For the preparation of Technical Code for Soil Mixed Wall, 8 shaped steel reinforced cement-soil test beams are selected and flexural tests are conducted. The test beams have two kinds of width, namely 200 mm and 100 mm. Friction-reducing agent is introduced into 4 test beams of the total 8 test beams. Two types of loading strategies are adopted. By performing the tests, the effects of the ratio of cross section area of the shaped steel to that of cement-soil, loading strategy and friction-reducing agent on the interaction of the shaped steel and cement-soil and the flexural behaviors of the test beams are investigated. Then the failure patterns and the contribution of shaped steel and cement-soil to the assembled stiffness of composite beams are studied. The test results show that the ratio of cross section area of shaped steel to that of cement-soil, loading strategy and friction reducing agent have significant effects on the assembled stiffness and failure patterns of composite beams. Finally, the recommendations on the consideration of assembled stiffness of composite beams in design are proposed.