Based on the economic and road freight traffic volume data of Shanghai between 1990 and 2005,a study is made of the relationship between road freight traffic volume and economy growth with the cointegration theory and Eviews software.A conclusion is drawn that there exists the long-term equilibrium between the road freight traffic and economy.The Granger causality test results show that there exists single Granger causality between road freight traffic volume and total road operation mileage,the total industrial enterprises,GDP.The impact of road transport on the economy growth is not remarkable.And the government should make more industry policy and road freight transport policy adjustment which can guide a more rational development for the road transport.