Chao Phraya River is a paramount river in Thailand, flowing through Bangkok and Gulf at 372 kilometres, carrying over 280 fish species.

The Chao Phraya has 5 main tributaries being the Pa Sak River, Ping River, Nan River, Tha Chin River and Sakae River.

It covers about 35 percent of the Thailand land with its watershed, which is divided into 5 basins and has created swamp forests at its low land areas.