中文摘要：

水安全和粮食安全是我国社会发展的关键，而虚拟水同时连接着粮食和水资源。针对水资源相对贫乏的国家，从水资源相对丰富的国家进口农产品的现象，应用机会成本和比较优势理论，通过对虚拟水贸易分析。提出虚拟水贸易不仅仅取决于资源含量和产品技术含量，还取决于各国贸易产生的机会成本。该方法能为我国政府制定最优的虚拟水战略提供有效的理论依据。

英文摘要：

Food and water security are the key in the development of our country, and virtual water connects food and water resources at the same time.As to the situation of virtual water trade in which water-scarce countries import directly agricultural products from water-rich countries, by using opportunity costs and comparative advantages principles and analyzing virtual water trade, it is figured out that virtual water trade bases not only on resources and production technologies but also on comparative advantages when evaluating opportunities to trade agricultural products.The result from the paper can provide reference for optimal virtual water strategies for our country.