In this paper, we have studied the features of fault gouges, the fault activity and the mode of fault slip in the eastern segment of Altun Fault Zone by means of the scanning electron microscope and X ray etc.. The results are as follow: 1) The activity has been decreasing from east to West in eastern segment of Altun Fault Zone since Late Pleistocene Epoch. 2) There were at least. 2-3 palaeoearthquakes during Quaternary Period. 3)The fault has been mainly in stick slip from Subei to Arkesai, and in creep slip from Bage Valley to Changma Dam since Holocene Epoch.