中文摘要：

为了解退耕还林工程对黄土高原生态脆弱区米脂县综合效益的影响，采用生态经济分析法、问卷调查法、修正的Bossel定位理论方法，2009年10～11月，对米脂县退耕还林工程实施前后的生态、社会和经济效益进行评价。研究结果表明，（1）自1998～2009年，退耕造林地土壤有机质（0～20 cm）平均含量和土壤有机碳密度分别比临近（﹤30 m）的坡耕地高出0.478％和0.574 kg/m2；（2）退耕还林经济净效益主要体现在退耕造林后劳动力转移劳务创收。即：69％的被调查农户家庭纯收入上涨了2～5倍，56％被调查农户种植业纯收入上涨0～1倍，44.5％的农户劳务收入占了家庭纯收入的50％以上，36.6％农户劳务收入超过了家庭纯收入的10％～20％，87.5％农户的退耕补贴占家庭纯收入的10％以下；（3）退耕还林提高了社会整体协调性0.81。国家实施退耕还林工程以来，初步改善了区域生态环境，整体提高了农户经济收入，优化了经济收入结构，但农业产业结构调整空间潜力很大。

英文摘要：

To understand the comprehensive benefits of the Grain for Green Project （GG Project） in MiZhi county of China ’ s northern Shaanxi Loess Plateau , by using an integrated approach of ecological economic analysis meth-od, questionnaire, and revised positioning theory raised by Bossel , the comprehensive benefits of this project was evaluated during 10~11 of 2009.The results showed that：1） In terms of ecological benefits , after the implemen-tation of GG Project from 1998 to 2009, the soil organic content （0~20 cm ） and soil organic carbon density （﹤30 m） increased by 0.478 % and 0.547 kg/m2 respectively; 2 ） In terms of economic benefits , it mainly contributed to providing more rural surplus labor for income generation . For sampled households , 69 % house-holds increased their net income 2~5 times, and the net income of 56%household fed by planting farmland rose by 0~1 times, and the 44.5 % households ’ labor income exceeded 50 % of their net income , 36.6 % house-holds’labor income exceeded 10 %~20 % of their net income, and subsidies from GG project accounted for 10 %of the net income of 87.5 % households; 3 ） The overall coordination functions of the society increased by 0.81.Since implementation of GG Project , regional ecological environment and the economic income of farmers have been improved and the structure of economic income has been optimized .