稻田系统除了提供市场必需的稻米外，还具有洪水防治、气候调节、有机废弃物处理、生物多样性保护、景观形成等多种生态服务功能。这些生态服务功能所形成的巨大的外部经济效果往往以水稻生产副产品的形式出现，政府和非农业人口一直在"消费"这些以公共产品形式存在的生态功能而无需向稻农支付任何额外的补贴或费用，基本上人们对它的消费是无意识的或认为是理所当然的，这种观念极大地降低了水稻生产的重要性，使稻田生态功能的可持续性受到损害。本研究旨在利用替代法（Substitution Cost Method，简称SCM）评价理论与方法建立稻田生态系统服务功能的经济评价系统，并根据该系统以江汉平原稻田为例计算其洪水防治功能和气候调节功能的货币化价值，为各级政府制订稻田生态服务功能的保全政策和惠农政策提供科学的定量决策依据，并丰富和完善环境价值评价的理论体系，对保障我国未来的可持续粮食安全有重要的现实意义。

Paddy rice cultivation with paddy field irrigation has multi-functional roles not only to provide food securely but also to maintain other ecosystem service functions, such as flood mitigation, climate regulation, resolution of organic waste, biodiversity conservation , recreation and amenity and so on. The huge external economic benefits generated by Ecological service functions are often presented by-product of rice. The government and non-agricultural populations consume the public benefits, unconscious or taken for granted, derived from ecosystem services, and unnecessary to pay. This tendency will influence the sustainable development of ecosystem services of paddy. This study is conducted to establish the economic value of the beneficial functions of paddy field ecosystem by substitution cost method, and estimating the economic value of flood mitigation and climate regulation of paddy of jianghan plain, which can provide scientific quantitative decision and reason for different levels government that institute security and benefit farming policy;and enrich and perfect the theory system of Environmental value evaluation;meanwhile, vital realistic significance to safeguard sustainable Food security future.