Trading is one of the most basic activities of mankind. It has existed in every society,every part of the world, and in fact every day since the caveman came into being. International trade is a business which involves the crossing of national borders. It includes not only international trade and foreign manufacturing, but also encompasses the growing services industry in areas such as transportation, tourism, banking, advertising, construction, retailing,wholesaling and mass communications. It includes all business transactions that involve two or more countries. Such business relationship may be private or governmental. In the case of private firms the transactions are for profit. Government-sponsored activities in international business may or may not have a profit orientation.

Trading has many forms of which the most traditional are merchandise export and import. Merchandise exports are goods sent out of a country, whereas merchandise imports are goods brought in. Since these are tangible goods that visibly leave and enter countries,they are sometimes referred as visible exports and imports. The terms exports and imports are used frequently, yet, in reality the reference is only to the merchandise exports and imports which are the focus of this book.

贸易是人类最为基本的活动之一，每个社会都有贸易活动，并存在于世界各地，事实上，从洞穴人开始就已经有了贸易交往活动。国际贸易就是人们跨越国界所进行的商务活动。广义地说，它不仅包括国际贸易及国外生产，同时还包括新兴的服务行业，诸如交通运输业、旅游业、银行业、广告业、建筑业、零售业、批发业以及大众传播业等。它包括所涉及的两个或两个以上国家的商务活动。这种商务活动，可能是私人间的关系，也可能是国家间的关系。私人企业为盈利从事国际商务活动，而带有国家色彩的国际贸易也可能不仅仅以盈利为目的。(www.daowen.com)

国际贸易有多种形式，其中最传统的是商品进出口。商品出口指货物输往国外，而商品进口则指货物输入国内。因为这些有形物品的输出输入都是看得见摸得着的，因此商品进出口有时又可称作有形进出口。虽然人们经常使用出口与进口这两个词，实际上，进出口一般指的只是商品的进出口，这也是本书阐述的主要内容。