This study intends to insist on the necessity of Regulatory Impact Analysis to the Assembly-introduced Bills which have been exempted from a detailed social benefit/cost analysis in Korea. With the various monitoring systems of Korean National Assembly like Legislation and Judiciary Committee, NABO(national assembly budget office), NARS(national assembly research service), We could not judge sufficiently whether the Bills bring to benefits over the costs to the society. Because these existed monitoring institutions does not adopt the logics of regulatory impact analysis which is useful to analyze costs and benefits of Bills. So, The growing number of bills introduced by assembly which are exempt from the regulatory quality process could be remedied by a permanent monitoring tools like Regulatory Impact Analysis in the National Assembly to assure oversight of the quality of laws.