Abstract: Taking 8 years old Apricot trees(Prunus dulcis) in Jiyuan city of Henan province as an example,the transpiration and water demand-supply of Apricot trees in the rocky mountain of Northern China was analyzed based on daily transpiration data,which was measured by thermal dissipation sap flow velocity probe(TDP),and daily precipitation data,which obtained by automatic meteorological monitoring system in 2005 and 2006.The results showed that transpiration rate(TR) of Apricot trees had significant daily variation,and the TR in sunny day was higher than that in cloudy day in the same growing season.The TR of Apricot also had obvious seasonal change,which was higher during growing seasons(April to August) with the maxim value at May or Jun and mini value at January or December.The difference between total precipitation and evapotranspiration of Apricot trees in experimental area were-263.25mm and-220.47mm in 2005 and 2006 respectively,which indicated that annual precipitation could meet transpiration of Apricot trees.But precipitation each month could not meet transpiration of Apricot trees except for July,August and September.

Key words: Apricot trees(Prunus dulcis), Apricot trees(Prunus dulcis), Transpiration rate, Difference between evapotranspiration and precipitation