The influence of external trade on economic growth has been one of debating problems in the economics field. On the basis of yearly economic data of import and export in shanghai from 1985 to 2004, this thesis studies the dynamic relations between external trade and economic growth and state the role of external trade played in economic growth by means of Co-integration Test, Vector Error Correction Model. The results of empirical analysis show that import and export can obviously propel the growth of GDP lagging one year, export has more contribu tions to promoting economic growth in the short run, but import has more contributions in the long term.