The thesis concentrates on measuring the benefits and losses of implementing regional trade agreements. In particular, the thesis analyses trade flow changes, foreign direct investment inflow changes, industrial total factor productivity changes and specific commodity trade flow changes in Australia and China. Four empirical studies are undertaken. Firstly, the thesis introduces the gravity model to estimate the effect of regional trade agreements on trade flow changes, focusing on thirty-nine countries and areas from seven regional trade agreements during 1980-2004. The results show that there are trade creation and trade diversion effects for various memberships. The results further show that China experiences an export creation effect for its APEC membership while Australia has an import diversion effect for its CER membership. When trade between Australia and China is considered, Australia's CER membership impedes its trade with China. However, both Australia and China benefit from attending APEC jointly to enlarge their bilateral trade. Secondly, a modified gravity model is undertaken to test the impact of regional trade agreements on foreign direct investment inflows to Australia and China. It uses the same regional trade agreements to that of the trade flow study for the period of 1980 to 2004 for Australia and 1985 to 2004 for China. The results show that CER members tend to strengthen their bilateral foreign direct investment cooperation after the implementation of CER trade and investment liberalization. Thirdly, the impact of regional trade agreements is examined on industrial total factor productivity growth. The findings show that industries with comparative trading advantages in both Australia and China tend to improve their total factor productivity upon liberalizing trade both bilaterally and multilaterally. However, industries with comparative disadvantages need more protection against severe foreign competition. It uses data from 1974-75 to 2004-05 for the Australian market sector analysis, from 1968-69 to 1990-2000 for the Australian manufacturing industry analysis, and from 1987 to 2003 for the Chinese industry analysis. Finally, the thesis investigates the impact of regional trade agreements on bilateral commodity trade between Australia and China from 1979 to 2004. A similar gravity model to that of the trade flow study is used, introducing an additional GDP per capita variable to capture the effect of increasing consumers' income on their consumption of particular goods and products type based on product and production characteristics. Both the one-digit and some detailed four-digit commodity classifications described in the Standard International Trade Classification are considered. The results show that participation in regional trade agreements is an important factor that affects Australia's major commodity trade with China. The major contribution of this thesis is the investigation of issues on trade flows and foreign direct investment specifically in Australia and China, together with the studies of the effect of regional trade agreements on industrial total factor productivity improvement and specific commodity trade changes. Due to the increasing pursuit of bilateral and regional economic cooperation in Australia and China, the results of this thesis are of particular importance to both countries in their foreign trade and economic strategies.