China is the world's most populous country with about 1.3 billion people—20 percent of the Earth's population. Occupying most of East Asia, it is the fourth largest country in area (after Russia, Canada, and the U.S.). China's geography is highly diverse, with hills, plains, and river deltas in the east and deserts, high plateaus, and mountains in the west. Climate is equally varied, ranging from tropical in the south (Hainan) to subarctic in northeastern China (Manchuria). China's geography causes an uneven population distribution; 94 percent live in the eastern third of the country. Shandong province, with its mild coastal climate, has 91 million people, but Tibet, with its harsh mountain plateau climate, has only 2.6 million. The coastal regions are the most economically developed—acting as a magnet for an estimated 90 million Chinese migrants from the poor rural interior.

China has perhaps the world's longest continuous civilization; for more than 40 centuries its people created a culture with strong philosophies, traditions, and values. The start of the Han dynasty 2,200 years ago marked the rise of military power that created an empire—one that provided a golden age in art, politics, and technology. Ethnic Chinese still refer to themselves as the "People of Han," and Han Chinese constitute 92 percent of the country's population. Successive dynasties developed a system of bureaucratic control that gave agrarian-based China an advantage over rivals. China remains a predominantly rural society, with only 39 percent living in urban areas.

The first half of the 20th century saw the fall of the last Chinese emperor, Japanese invasion, World War II, and civil war between Chinese Communist and Nationalist forces—ending with the retreat of the Nationalists to Taiwan. The People's Republic of China from 1949 to 1976 imposed state control on the economy. Since 1979, China has reformed its economy and allowed competition, and today has the world's highest rate of growth. Rapid industrial development has increased pollution—with China having seven of the world's ten most polluted cities. The largest producer and consumer of coal, the country is turning away from coal toward clean hydroelectric resources, such as the Three Gorges Dam. Politically it still maintains strict control over its people. Chinese rule over Tibet remains controversial, fighting with Muslim separatists in Xinjiang continues, and political issues with Taiwan remain unresolved. China regained Hong Kong from Britain in 1997 and Macau from Portugal in 1999. In 2003 China became only the third nation (after Russia and the U.S.) to launch a manned spaceflight—with plans to reach the moon by 2010.