Abstract: The Canton System of trade, which was first implemented in the twenty second year of the Qian long Reign, was directed at foreigners in the Guang zhou area Scholars have commonly considered it a closed- door policy to restrict both inland and overseas trade How ever, are examination of the Canton System shows that it was an effective fo reign policy to control foreigners and ami ed to keep order in the frontier port of Guangzhou and the southeast coast- line of China as well .In the same year, Zungar War was launched to resolve the crisis on China s' Northwest border. This indicated interactivity between foreign and domestic policies and the resolution of important domestic problems.