Geographys

Mekong countries

The six countries on Southeast Asia’s great river, from the Tibetan Plateau to the delta in southern Vietnam: two that hold the dams upstream, and four that live off its fish and floods below.

6 countriesAs of September 2026Short notes, not sourcedSuggest a correction

The 6 countries shaded; the smallest are dots.

The Mekong is about 4,800 km long, the longest river in Southeast Asia. It rises on the Tibetan Plateau in China, where it’s called the Lancang, and reaches the South China Sea through a maze of channels in southern Vietnam.

It is one of the world’s most productive rivers for fish, and tens of millions of people depend on it for food. China has built a chain of large dams on its upper reaches and Laos has dammed the main stream too, which worries the countries downstream about the fish, the sediment that feeds the delta’s rice fields, and how much water arrives in the dry season.

A clue in The Grid: On the Mekong →

Upstream2

Where the river runs fast through deep gorges.

  • Flag of China
    China

    About half the river’s length is in China, in Tibet and Yunnan, where the Lancang runs in deep gorges beside the Salween and the Yangtze, three great rivers squeezed within about 70 km of each other.

  • Flag of Myanmar
    Myanmar

    Its only stretch is a short one along the border with Laos, ending at the Golden Triangle, where Myanmar, Laos and Thailand meet on the river.

Downstream4

The four members of the Mekong River Commission, set up in 1995 to manage the lower river together.

  • Flag of Laos
    Laos

    The river runs the length of the country, past Luang Prabang and Vientiane, and much of it is the border with Thailand. Laos has built dams on the main stream to sell electricity to its neighbours.

  • Flag of Thailand
    Thailand

    The Mekong forms long stretches of its border with Laos in the north and north-east, and the first Friendship Bridge between the two opened in 1994.

  • Flag of Cambodia
    Cambodia

    Phnom Penh is where the Tonlé Sap river joins the Mekong. In the rainy season the Mekong’s floodwater pushes the Tonlé Sap backwards and swells the Tonlé Sap lake to several times its dry-season size.

  • Flag of Vietnam
    Vietnam

    The Mekong Delta, where the river splits into many branches, grows about half of Vietnam’s rice. Most of it lies only a metre or two above sea level.

Close calls

Khone Falls

Just north of the Cambodian border, in southern Laos, the river drops over the Khone Falls, the widest waterfall in the world by some measures. Its many channels stop ships from sailing the whole river, which is why French plans to use the Mekong as a route into China in the 1860s came to nothing.

Tibet

The source lies in Qinghai province, on the Tibetan Plateau, and the upper river runs through the Tibet Autonomous Region, both part of China and both counted in China’s share.

Giant fish

The Mekong has more species of giant freshwater fish than any other river, among them the Mekong giant catfish and the giant freshwater stingray. The biggest freshwater fish ever recorded, a stingray of about 300 kg, was caught in Cambodia in 2022.

More country lists

Know a better source? Send a link for any fact on this page.
Primary sources (treaties, court rulings, official records) help most.