In the Tibetan Plateau， many lakes have shoreline， erosion terraces and high-level lake sediments. These geomorphologic and sedimentary units are direct geomorphologic and lithologic evidence for the changes of lake surface in geological history. These landforms and sediments not only reflect the hydrological history of the lake， but also serve as important archives to reveal regional and global environmental changes. Lake Nam Co is the most typical and representative lake system on the Tibetan Plateau. The highest abandoned lacustrine sediments along Lake Nam Co coast lie about 150 m above the modern present lake level and 123 m above the present topographic threshold. A series of scientific issues， such as the times of the abnormally high lake-level， the transgression and regression processes of lake， the drivers of the extreme high-level events， and the hydrologic connection with other lakes， remain ambiguous or controversial. Here， we focus on the the abandoned high-level lacustrine sediments along Lake Nam Co coast. The issues of characteristics， ages， processes and driving mechanisms of lake-level changes at Nam Co were commented. Furthermore， the focuses of researches in future were presented. Finally， based on our preliminary investigations， we suggest that the high-level lake sediments around the Nam Co coast may be formed during the middle to late Holocene， indicating one transgression and regression process. The anomalous oscillation of the India-Burma Trough and relevant high snowfall may be the main driver of lake-level variation.