The merger between enterprises is one of the common ways among the firms in order to increase company size, development activities, perform a variety of savings, decrease costs and improve efficiency and synergy. For this reason, some developing countries have prepared programs to encourage firms to merge together with the purpose of increasing the size of its domestic firms and improving their international competitiveness in the face of some developed countries' large firms.
However, the integration of entities sometimes omits competing firms, eliminates competition and creates a monopoly in the domestic market which in turn, in addition to a waste of resources and increase social expenditures will lead to higher prices and violate consumers' rights. According to this, mergers are of different effects on markets. This article intends to study the legal aspects of a merger between firms from the perspective of South Korean competition law. Korea, as a developing country has experienced interesting successes in this field and its experiences, will be useful for Iranian economic and competition policies.