Materials Industry has a very large ripple effect on national economic development. Nevertheless, Korea has been passing over importance of this Industry. So, this study examined competitiveness on ten chief exporting items to U.S.A market based on the understanding of vital role of materials industry in the national economy. Analyzing methods were Market Share, Trade Specialization Index(TSI), and Market Comparative Advantage(MCA) and the data were collected through parts and materials statistical data which produced by Korean Commerce and Industry Minister. From this study, following results were found. i) Highly ranked items of U.S.A market share were chemical fiber drapery weaving, synthetic fiber. These items commanded over 10% share of the same market and tire, steel wire occupied 9.05%, 8.65% respectively. ii) In searching trade balance aspects through TSI, tire and steel wire secured very powerful competitiveness among examined items in trading with U.S.A. while synthetic resins and other plastic material were very weak competitiveness in the same market. iii) Analysis results of market competitiveness by MCA, indicated that chemical fiber drapery weaving, synthetic fiber and tire ensured high-powered competitiveness in U.S.A Market. Therefore, these items would be positioned as main items in the market.