The inner-structure of glacier was analyzed from the profile images of ground-penetrating radar at No.12 Glacier in Laohugou Qilian Mountain western China. By calculating the difference of dielectric constants among water, air, bedrock, debris and ice, integrated with changes in radar wave polarity and velocity, the geomorphic character within the glacier was described and caves, caves with water, channels beneath the ice, the interface between glacier and bedrock were identified and positioned, with the comparison of wave patterns introduced in some literatures. The results suggest that there exist debris layers between ice-bedrock interfaces indicating that strong basal erosional processes may even prevail in certain part of a glacier of the continental characteristic, contrary to the early knowledge about this kind of glaciers.