The construction of expressway results in the changes of the ecosystem service value via changing the land use types.Based on the classification and evaluation method of global land ecosystem service value first used by Costanza et al.(1997) as well as ecosystem service values of unit area of each land use type estimated by Chinese scholars,the changes in ecosystem service value of different land use types were evaluated after the construction of the Huxian-Mianxian section of Xi'an-Hanzhong expressway.During the construction,1116.4 hm² farmland,6.8 hm² orchard,1²5.² hm² woodland and 1²5.8 hm² grassland were used.However,after the construction,areas of the woodland and grassland were increased by 155.3 hm² and ²1.4hm²,respectively,due to vegetation restoration and landscaping.The ecological service values of climate adjustment,habitats,and recreation increased due to increases in woodland and grassland areas.The construction nullified the ecosystem service value of farmland and orchard,which reduced ecological service functions of biological control,food supply,and pollination by 90%,73%,and 6²%,respectively.In general,the overall ecosystem service value tended to decrease,about 1400 yuan per year per kilomemter after the construction of the expressway.However,the loss of ecosystem service value is expected to be far less than the economic and social benefits that the expressway can bring to the area.