Hoagland solution was used to determine the root morphology properties of Rorippa globosa (Turcz.) Thell. and Rorippa palustris (Leyss.) Bess. Under the conditions of Cd spiked at 2.5 and 5 mg kg(-1). R. globosa showed all hyperaccumulative characteristics and was a Cd-hyperaccumulator. In contrast, R. palustris was a non-hyperaccumulator. The total root lengths, total root surface areas and total root volumes of R. globosa were not significantly decreased (p<0.05) compared to the control when 2.5 and 5 mg kg(-1) of Cd added. However, these 3 indexes of R. palustris were all significantly decreased (p<0.05) when 2.5, 5, 10, 20 and 40 mg kg(-1) Cd added compared its control. The average root diameters of R. palustris and R. globosa were not affected by Cd. These results showed that root morphology might be a factor of plant with strong tolerance to Cd. (C) 2012 Elsevier Ltd. All rights reserved.