Abstract: With the shortage of water resources in the process of urbanization，urban agriculture is playing an important role in improving urban ecosystem services and maintaining urban ecological health and its sustainable development. The paper evaluates and analyzes the water conservation service of Xi’an urban agriculture in 2011 by employing the socioeconomic and geographical data in survey region，captured from statistical yearbooks，meteorological database，investigation，DEM and TM. The results show as follows：（1） the total volume of water conserved by urban agriculture is up to 16.6×108 m3 in Xi’an urban agriculture zone，and its monetary value is by 1.05×108 yuan in the year of 2011；（2）the capacity on water conservation service obviously varies from counties and districts in Xi’an urban agriculture zone，the following counties or districts are the main contributors to total values：Zhouzhi，Lantian，Huxian，Lintong and Chang’an；（3） a large proportion of total value from water conservation service are provided by crop land，and the largest is orchard in per unit area；（4） there are significant spatial patterns of water conservation service of urban agriculture zone，its higher value in the eastern and the western of the research region，and lower one in the central；（5） the spatial pattern of the urban agriculture zone is opposite to that of the urban district，suggesting that urbanization could be of great disservice to urban agriculture development. In conclusion，the models were established by considering the water storage coefficients among different types of agriculture，the capacity of precipitation and evaporation in the region and the crop area comprehensively，by which the models should be able to enhance the completeness and promote the accuracy in measuring the capacity of water conservation service of urban agriculture zone. Also taking into account the increasing shortage of the land resource in the urban and suburb，the water conservation coefficients are led between the agricultural land and the built-up land in order to evaluate the monetary value accurately and correspond to the regional situation better.

Key words: urban agriculture, water conservation service, Xi’an urban agriculture zone