Abstract: Researching and producing the field test instrument for reinforced plastic geogrid for concrete block retaining walls is reported in this paper. Several pieces of reinforced plastic geogrid for concrete blocks were tested in the field of Xinyi Changxin railway. The test result shows that two kinds of forms to link geogrid and concrete blocks (embedding form and tied ring form) are practicable. The tensile strength of geogrid in field is 30%~40% lower than that in laboratory and the reason is discussed.