Lake sediment is important archive for reconstructing the past climate change, in which the chronological framework of sediments is the basis. Varve is a kind of sedimentary lamina formed in pairs in lake sediments, usually with one year as a cycle. Supported by the projects the Strategic Priority Research Program of Chinese Academy of Sciences “Pan-Third Pole Environment Study for a Green Silk Road (Pan-TPE)” and The Second Tibetan Plateau Scientific Expedition and Research, the authors obtained a 1-meter long sediment gravity core from Jiangco in the central Tibet Plateau, and found well preserved varves. Subsequently, core thin sections were made, and the varve and its thickness were counted and measured to obtain the chronological sequence from 81 A.D. to 2015. The precipitation in this area in the past 2000 years has been reconstructed by using the percentage of coarse-grained layer thickness in the total varve thickness, which represents the precipitation. High resolution and high-precision chronology and precipitation records can provide reliable background of climate and environmental change, and provide reference for paleoclimate simulation and the rise and fall of ancient civilization.