Abstract:The water-retention characterstics, saturated hydraulic conductivity and water evapoiation of three orange-orchard red soils in centaal Zhejiang, Chiua, and the effect of soil conditioners on aggregation and evaporation of the soils were studied under laboratory conditions. The resups showed that the water-retention capacity of the soils was positively correlated with <0.01mm physical clay content (r=0.933**), and the saturated hydraulic conductivity of the soils was very highly correlated with mean weight-diameter (MWD) (r=0.956**) and the destruction percentage of soil aggregates (r=-0.996**). When soil suction ranged from 50 to 100 kPa, irrigation would beweeded for citrus. Application of soil conditioners increased >0.25mm waterstable aggregates and MWD, and the order of the effectiveness was polyvinyl alcohol (PVA)>polyproyreneamide (PAM)> hydrolytic polyacrylonitrile (HPAN). The sequence of reduction of average daily evaporation due to application of soil conditionerwas quaternary yellow clay>purple sandstone soil>red sandstone soil.