China stretches some 5,026 kilometres (3,123 mi) across the East Asian landmass. China is bordered by seas and waters eastward, with the East China Sea, Korea Bay, Yellow Sea, Taiwan Strait, and South China Sea, and bordered by landmasses on its 3 other sides, from North Korea to Vietnam. China has been officially and conveniently divided into 5 homogeneous physical macro-regions: Eastern China (subdivided into the northeast plain, north plain, and southern hills), Xinjiang-Mongolia, and the Tibetan-highlands. Its physical features are multiples. The eastern and southern half of the country, its seacoast fringed with offshore islands, is a region of fertile lowlands and foothills with most of the agricultural output and human population. The western and northern half of China is a region of sunken basins (Gobi, Taklamakan), rolling plateaus, and towering massifs, including a portion of the highest tableland on earth (Tibetan Plateau) with lower agricultural possibilities and thus, far less populated.
Traditionally, the Chinese population centered around the Chinese central plain and oriented itself toward its own enormous inland market, developing as an imperial power whose center lay in the middle and lower reaches of the Yellow River on the northern plains. More recently, the 18,000-kilometers coastline have been used extensively for export-oriented trade, making a power shift, with the coastline provinces becoming the leading economic center.
With an area of about 9.6 million km², the People's Republic of China is the 3rd largest country in total area behind Russia and Canada, and very similar to the United States. This figure is sometimes challenged by border disputes, most notably about Taiwan, Aksai Chin, the Trans-Karakoram Tract, and South Tibet.