This paper draw tasks and policy implications including unity expense through foresight of the reunification as concept hereafter of unification of South and North Korea. Namely, in this study we attempt to system dynamics technique for analysis how will system change of south and north Korea and unity expense effect affect stability of Unification of South and North Korea. In particular, considering a sudden regime collapse time and after that time as the unification time and after that time respectively we approach with a focus on change process of North's system. In order to achieve the purpose of this study we attempt to make set of the causal maps and simulation analysis by Dynamic Modeling since is considered to be important the systematic thinking of system change of north Korea. To obtain an objective and valid study we analyze Vensim PL version of the computer program for approaching Normalized Unit Modelling By Elementary Relationship. Changes be found in system of south and north Korea in the unification time and after that time, that is to say dynamics occurring in limited and complex structure of system of South and North Korea as casual loop feedback structure is explained.