In 2003, "The National Land Use and Planning Act" (NLUP Act) was enacted unifying two old laws; "The Urban Planning Act" enacted in 1962 and "The National Land Use and Management Act" enacted in 1972. One of main reasons of unifying two acts was to extend urban planning-based development systems to rural areas for preventing uncontrolled urban sprawl in rural areas and enhancing or settlling plan-based land use system in rural areas. This paper is conducted with the following specific objectives: i) to critically review the contents of NLUP Act in terms of rational rural land use planning; ii) to evaluate plan-based land use practices in rural area by NLUP Act; iii) to appraise performance level for prevention against unplanned development activities in rural areas by NLUP Act. To accomplish these objectives, we surveyed actural state of rural land use and development system by the new act in two case study areas. Ansung city in Gyeongi province as an urban sprawl region and Hamyang county in Gyeongnam Province as a remote rural area. Study results ascertained that the new act can not effectively control rural land use and not prevent over-use of agricultural land in the positive and effective ways because of followering three points.