The purpose of this study was to develop the model of developing National Competency Standards and verify the model through developing NCS in Construction Work. This study was carried out the theoretical review, developing method, a panel of expert committee. Final results were as follows. First, NCS(National Competency Standards) was required to improve and develop the vocational skills in industry fields and to connect the relation between vocational education training and qualification system. Second, the objective and verified model of developing NCS was needed and the possibility of applying ISD was verified. The model was consisted of five steps which was analysis(plan for development, analysis of field characteristics, analysis of skill level and type, job analysis), design(NCS format design, competency unit design), development(standardization, measurement of key competencies, establishment of skill level, coding), implementation(practical application, spread) and evaluation(verification, and efficiency analysis). Third, NCS of Construction Work was consisted of plan for Brick Laying, Plastering, Water Proofing, Tile Laying. Painting, Reinforcing Bar, Concrete, Joinery, Carpentering based on the analysis of skill level and type. There are 10 competency units cluster and 83 competency unit in NOS of Construction Work.