Laos is 80% mountainous and plateau, and most of it is covered by forest, so it is called "the roof of zhina". The terrain is high in the north and low in the south, bordering China's western Yunnan Plateau and Yunnan in the north, the plateau formed by Changshan Mountains in the east, and the basins and small plains along the Mekong River basin and its tributaries in the west. From north to south, the whole country is divided into upper Liao, middle Liao and lower Liao. Shangliao has the highest terrain, with the elevation of Chuanqi Plateau of 2,000-2,800 meters and the highest peak of Pubiya Mountain of 2,820 meters.

After long-term erosion in mountainous areas and plateaus, most peaks are round and the erosion surface of plateaus is developed. The plain is formed by alluvial rivers, with a vast area and low terrain. The river network in the delta is densely covered, swamps are everywhere, and it is rapidly expanding to the ocean.