Characteristics of radial oxygen loss (ROL) from root of 10 wetland plants was studied in this paper.Root ROL varied with the distance from root tips,as well as with species.Spatial pattern of ROL was identified to show 3 types according to the trends of ROL rate along adventitious roots.Type Ⅰ showed a relatively high rate of ROL along the whole root,declining gradually from root apex to root basal part.Type Ⅱ was indicated by significantly high ROL in root apex but decreased greatly towards root base.As for Type Ⅲ,ROL was similar but very low along the whole root.In nutrient solutions,deoxygenation caused a series of changes in root ana-tomy of some species,such as increased root diameter,root porosity and more developed aerenchyma,inducing a ROL barrier in root basal part and the consequent change of ROL profile.