Climate change not only affects the changes of water resources and its spatial and temporal distribution,but also will increase the crop evapotranspiration and thereby increase the contradiction between supply and demand of agriculture water resources.Therefore, study on impacts of climate change on agriculture water requirement in irrigation destrict will have a great significance on the protection of agricultural water''s security. Using the weather data of 28 years from 11 weather stations in Baojixia irrigation district in Shaanxi Province, the article analyzed the characteristics of climate change in irrigation destrict, calculated the main crop water requirement and the farmland net irrigation water requirements and also used the sensitivity analysis to study the impacts of climate change on agriculture water requirement. The results show that there is significant increase on annual temperature,and sustained decrease on precipitation,and increase on evaporation.The relative humidity and wind speed in most regions is significant trend of decline,while sunshine duration is increasing trend. The water demand of wheat,corn,cotton and canola at growth stage show clear upward trend. The influence of weather factors on farmland net irrigation water requirement is as follow:precipitation>relative humidity>maximum temperature>sunlight hours>mean temperature>wind speed. Increase of temperature,dropping in relative humidity and precipitation,and increase in sunshine duration will result in obvious increase in main crop water requirements. As crop planting area decrease, agriculture water requirement has a trend of decrease.