Originally the Interactive Activation Model(IAM) was developed to expalin Word Superiority Effect(WSE) in the English words. It is known that there is a similar phenomena in Korean characters. In other words people perceive a grapheme better when it is presented as a component of a character than when it is presented alone. We modified the orginal IAM to explain the WSE for Korean characters. However it is also reported that the degree of WSE for Korean characters varies depending on the type of the character. Especially a components was reported to be hard to perceive even though it is in a context. It was supposed that this special phenomenon exists for WSE of Korean characters because Korean character is a two-dimensional composition of components(graphemes). And we could explain this phenomenon by introducing weights for the input stimulus which are calculated by taking into account the two-dimensional shape of the character.