1. Trade surplus promotes economic growth. First, the current account trade surplus stimulates economic growth. First, the current account trade surplus stimulates domestic aggregate demand and promotes economic growth. The current account trade surplus mainly comes from the increase of net exports, which is the result of the rapid growth of China's foreign trade, especially exports. The increase of net export makes the domestic total demand expand, and the expansion of domestic total demand promotes the growth of national economy. Second, the multiplier effect of net exports has expanded the scale of economic growth. The current account trade surplus is mainly the result of the increase in net exports. The increase of net exports has a multiplier effect on foreign trade. Under the effect of foreign trade multiplier, the scale of economic growth is several times that of net exports, and it is greater than the current account trade surplus. Secondly, the trade surplus of capital account directly promotes economic growth. First of all, the trade surplus of capital account directly increases aggregate demand and promotes economic growth. The trade surplus of capital account comes from the increase of net capital inflow, which is mostly the result of the increase of foreign direct investment in China. The net inflow of capital increases the investment demand in the total domestic demand, which directly promotes the growth of the national economy. Second, the multiplier effect of foreign direct investment has expanded the scale of economic growth. Under the effect of foreign direct investment multiplier, the scale of economic growth is several times that of foreign direct investment, and it is greater than the trade surplus of capital account. 2. The trade surplus increases the foreign exchange reserves, enhances the comprehensive national strength, helps to maintain the international reputation, and improves the ability of foreign financing and introducing foreign capital. Since 1994, China's balance of payments has maintained a trade surplus, except for 1998, which was affected by the Asian financial crisis and caused a deficit in capital account. With the increase of trade surplus, foreign exchange reserves are also growing rapidly, and by the end of 2003, foreign exchange reserves have exceeded 4 billion/kloc-0 billion dollars. The increase of foreign exchange reserves, first of all, strengthens the comprehensive national strength and puts China in a more favorable position in economic globalization. Second, it shows that China has good international debt paying ability, and it can easily obtain various loans at lower cost when financing in the international market. Thirdly, foreign investors who invest directly in China feel safe in repatriating profits. These foreign investors are willing to inject capital more actively, which is beneficial for China to introduce foreign capital. 3. The trade surplus is beneficial to the balance of economic aggregate. The balance of economic aggregate is not only related to savings and investment, but also related to foreign trade. When there is a fiscal deficit, when savings are completely converted into investment, it is necessary to make up for the fiscal deficit by increasing imports to maintain the balance between supply and demand of the total economic output. In that case, it is easy to have the twin deficits phenomenon that fiscal deficit and foreign trade deficit coexist. When there is a fiscal deficit, it is necessary to reduce imports or increase exports (that is, increase net exports) to make up for the fiscal deficit, so as to ensure the balance between supply and demand of the economic aggregate. The reality in China is that savings are not fully converted into investment. Since 1998, the proactive fiscal policy has been implemented year after year, and the fiscal deficit has increased year by year, so the increase of trade surplus, especially the increase of net exports, has partially made up for the fiscal deficit. Using the trade surplus to make up the fiscal deficit is not only beneficial to the balance of the national economy, but also can avoid the twin deficits phenomenon. 4. The trade surplus has enhanced China's ability to resist the risks of economic globalization and contributed to national economic security. The trade surplus for many years has increased China's foreign exchange reserves and made China an international creditor. Therefore, China not only has enough foreign exchange to meet the needs of foreign economic and trade, but also increases China's external solvency and ensures external payment, which is also conducive to coping with international financial risks and improving the country's ability to resist various economic risks. 5. The trade surplus is conducive to the stability of RMB exchange rate and the implementation of relatively loose macro-control policies. First, the trade surplus enables the country to have enough foreign exchange to intervene in the foreign exchange market and maintain the stability of the RMB exchange rate. Second, the state has enough foreign exchange to adjust the balance of payments and implement a proactive foreign trade and economic policy. Third, the trade surplus has enhanced the effect of the proactive fiscal policy. Due to the efforts of local governments at all levels in China to attract investment, the capital mobility of China is actually relatively large. In the case of high capital mobility, the trade surplus strengthens the effect of active fiscal policy to stimulate aggregate demand and promotes the rapid development of the national economy. That's all, the rest are shortcomings.