The mega-polis of Shanghai, lies in eastern China, on the Huangpu River (a tributary of the Yangtze River), near Yangtze’s mouth to the East China Sea. Shanghai (Chinese for 'on the sea') commands the entrance to the Yangtze River Basin, a large, populous, and economically productive region in central China. Shanghai is China’s most important port, commercial hub, and industrial center. Shanghai has hot, rainy summers and dry, cool winters.

Shanghai is an independently administered municipal district of 6,341 sq km (2,448 sq mi). It includes nine counties and 12 urban districts of the city proper. The urban districts cover 2,057 sq km (794 sq mi), of which about 300 sq km (about 116 sq mi) is built-up and densely populated. This area is expanding as a result of many construction projects in Shanghai. The municipality includes about 30 islands in the Yangtze River and along the coast of the East China Sea. The largest, Chongming Dao, constitutes one of Shanghai’s nine counties.

Shanghai is one of the most populous cities in the world, and the largest in China. At the turn of the century, Shanghai's population was reported to be on the 10 million mark, but in December 2003, the Mayor of Shanghai announced that it had surpassed 20 million!

The oldest section of Shanghai, near the confluence of the Huangpu River and the Wusong River (Suzhou Creek), reflects the city’s preindustrial growth as a walled center of trade and county seat. Shanghai grew west, south and north from this area, and the newer sections, typically with gridlike streets, are a result of the city’s growth as a center of commerce, shipping, and industry. After the Communist takeover of China in 1949, the development of Shanghai’s infrastructure languished, as revenue generated in the city was used to support other areas of China. As a result of economic reforms in the late 1970s, however, Shanghai’s suburbs began to grow.

Shanghai is one of China’s leading centers of learning and culture. There are more than 130,000 students in higher education in Shanghai and there are more than 50 institutions of higher learning. These include some of China’s most famous universities, such as Fudan University (founded in 1905), Tongji University (1907), and the East China Normal University (1951). A large branch of the Chinese Academy of Sciences is located in Shanghai, and extensive research is undertaken in areas such as semiconductors, lasers, nuclear energy, and electronics.

As a result of economic reforms that began in the 1970s, the amount of commerce and trade in Shanghai has increased dramatically. Shanghai now has a stock market, several foreign banks, and a variety of hotels, clubs, bars, and restaurants. Since 1990 the central Chinese government has encouraged foreign investment by relaxing regulations and lessening bureaucratic procedures. Investment in Shanghai has increased substantially, giving rise to a huge construction boom. Retailing has also mushroomed, and the city now offers many of the finest department stores and shops in China.

Shanghai began more than 1,000 years ago as a fishing village. It was officially designated a market town in 1074 and a market city in 1159. The main activities at the time were fishing, farming, craftworking, and commerce and shipping. By 1292 the region and market city had grown to the point where a separate county of Shanghai was designated, and the market city became the county seat. This permitted the city to assume the important duty of tax collection.

Shanghai continued to grow during the Ming dynasty (1368-1644), and near the beginning of the 15th century the county had an estimated 64,000 households. A new channel was cut north to the Yangtze in order to permit better drainage and to keep the outlet to the Yangtze and the East China Sea from filling with silt. This also provided a much more reliable and shorter channel for river traffic to the Yangtze.