In South Korea, the incentive scheme for generators to add new power generation is based on the system marginal price (SMP) and the capacity payment (CP). The infra-marginal generators receive an extra margin due to the high SMP level and the new infra-marginal generators need to be built to achieve the optimal fuel mix. However, the Metropolitan zone needs more marginal generators due to the transmission congestion and environmental regulations, but the marginal generator in the Metropolitan zone does not have adequate profits for the new investment under the current GP. This paper suggests the appropriate investment incentive scheme for different zones. The introduction of forward capacity markets for different regions creates higher capacity market prices in the Metropolitan zone than those in the Southern zone. The introduction of forward capacity market also induces a new LNG generator investment in the Metropolitan zone while only new infra-marginal generators need to be added in the Southern zone. (C) 2012 Elsevier Ltd. All rights reserved.