This document summarizes transboundary aquifers in Asia. It describes several major transboundary aquifers shared between countries in Asia, including the Ertix Valley Plain Aquifer shared between China and Kazakhstan, the Yalu River Valley aquifer shared between China and Korea, and the Middle Heilongjiang-Amur River Basin aquifer shared between China and Russia. As a case study, it then provides more details on the Middle Heilongjiang-Amur River Basin aquifer, including its geography, climate, river systems, groundwater resources, quality, and importance as a water source.