Abstract: The collapse features of the Ngangla Ringco Lake in northern Xizang are interpreted with the aid of the Landsat images,thus resulting in the determination of the indicators for the image interpretation.Six stages of the lake collapse are traced out in the light of the collapse traces in the lake.It can be seen that the gradual collapse of the lake should be attributed to the dry climates,alluvial fillings and ruoff loss caused by the large-scale uplifting of the Qinghai-Xizang Plateau.This study is significant to the understanding of not only the cause,velocity and degree of the lake collapse but also the dynamic regimes and regional changes of water resources and environments.