Competitive electricity markets create the new industry structure and business environment, which require a new type of regulation system. For rational division of duties between general competition agency and sector-specific regulator, static comparative advantage, synergy effect and dynamic aspects need to be considered. A critical condition for efficient regulatory institutions is independence. The grounds for the need of independence can be obtained from the theory of regulation and credibility issues. The scope of regulation in electricity industry of UK can be categorized into the entry regulation, the regulation for promoting competition, the regulation for consumer protection, the monopoly sector regulation, the regulation for public interests, and the regulation on power exchange and transmission network management, where OFGEM plays an essential role. For the improvements of the present regulation system of electricity industry, active role of the Korea Electricity Commission is required in consumer protection, public interests, entry regulation, monopoly regulation, and investigation of unfair behavior. The Korea Electricity Commission needs independence and rational division of duties between itself and Korea Fair Trade Commission.