This article analyzes the lock-in factors and their advancement direction of Korean energy innovation system(EIS), using case-study methodology. As the lock-in factors, which have been structural and complicated ones in the developing process of Korean EIS, are postulated government policies, market, industrial network, and demand condition. The lock-in phenomena result from connecting and conflicting incompletely among government policies, competing and controlling oligopolistically in market, constructing insufficiently in intra-industrial value-chain, and lowering in demand efficiency. To cope with these lock-in structure, connection among government policies, activation in market competition, coordination of industrial structure for added values, and uprading in energy efficiency are needed.