The population of South Korea is 48,422,644 (2005 estimate). The country’s population density of 493 persons per sq km (1,277 per sq mi) is one of the highest in the world. The majority of the population lives in the southern and western parts of the country.

The annual rate of population increase in South Korea has dropped steadily from more than 3 percent in the late 1950s to 0.38 percent in 2005. Urbanization of the country has proceeded rapidly since the 1960s, with substantial migration from rural to urban areas; 80 percent of the population is now classified as urban.

Following the official division of the Korea Peninsula in 1948, about 4 million people from North Korea crossed the border to South Korea. This sudden population increase was partly offset over the next 40 years by emigration from South Korea, especially to Japan and the United States. However, South Korea’s burgeoning economy and improved political climate in the early and mid-1990s slowed the high emigration rates typical of the late 1980s. Many of those who emigrated chose to return to South Korea.