The phenomena of strain accumulation in the specimen when tested by graded loading is studied through two group of comparative experiments

and then the influence of this phenomena on the dynamic shear modulus and damping ratio of the soil is analyzed. It is pointed out that because of the accumulation of shear strain

the hysteresis loops gained by graded loading method will shift along the shear strain axis as soon as the load grade number increases

while at the same time

the shape character of those loops will keep unchanged. The method of how to deal with the original data produced by the graded loading test is discussed. According to the results of the comparative experiments

it is concluded that the shear strain accumulating under comparatively small amplitude loads does little with the dynamic shear modulus and the damp ratio gained by the large graded loading test later. Lastly

the signification of the graded loading test method and its application to the soil dynamics research are discussed.