This dissertation first conducted a literature review for both the theoretical developments and the empirical studies of the Heckscher-Ohlin theory of trade; then employing the Leontief methodology and regression analysis investigated the factor contents and commodity compositions of the U.S. interregional trade flows. In accord with theoretical developments, the factor contents of regional trade were studied in forms of the Leamer hypothesis, the Vanek rank order hypothesis, the trade as a substitute for factor movement hypothesis and the Horiba triangular trade hypothesis; the commodity compositions of regional trade were studied by the OLS and Probit analysis. The advantageous attributes of regional approach over the international approach were stressed and its implications to the past and future empirical studies were discussed
