Under the effect of periodic cycle load, the frozen soil exists hysteretic characteristics. According to the research, the five parameters which are the residual strain , the numerical of short axis to long axis of the hysteretic curve , the slope of the hysteretic curve long axis k, the distance of adjacent hysteretic curve center point d and the area surrounded by hysteretic curve S are used to quantitatively represent the morphological characteristics of the hysteretic curve. The hysteretic curve of frozen soil is not a standard ellipse. Its morphological characteristics relate to the initial loading position. The morphological characteristics of the hysteretic curve of different soil affected by frequency, confining pressure and dynamic stress amplitude are different.