It is generally believed that Paleolithic man began to inhabit the Korean Peninsula about 40,000 to 50,000 years ago, although it has yet to be confirmed if they were the ethnic ancestors of present-day Koreans. Some Paleolithic men lived in caves, while others built structures on level ground. They lived on fruit and edible roots and by hunting and fishing.

Neolithic man appeared in Korea around 4000 B.C., with signs of their active presence around 3000 B.C. being found across the peninsula. It is believed that the Neolithic people formed the ethnic stock of the Korean people.

Neolithic people dwelled near the seashore and riverbanks before advancing into inland areas. The sea was their main source of food. They used nets, hooks and fishing lines to catch fish and gather shellfish. Hunting was another way to procure food. Arrowheads and spear points have been found at Neolithic sites. Later, they began to engage in farming using stone hoes, sickles and millstones.

Rice cultivation started during the Bronze Age, generally thought to have lasted in Korea until around 400 B.C. People also lived in thatch-covered pits, while dolmen and stone cist tombs were used predominantly for burials during the period.

As agriculture became a principal activity, villages were formed and a ruling leader with supreme authority emerged. Law became necessary to govern the communities.

In Gojoseon (2333 B.C.-108 B.C.), a law code consisting of eight articles came into practice, but only three of the articles are known today: First, anybody who kills another shall immediately be killed. Second, those who injure another's body shall compensate in grain. Third, those who steal other's possessions shall become a slave of their victim.