Wetland plants have a series of physiological and anatomical characteristics to adapt flooding conditions (or environments), e.g., aerenchyma in shoot and root and radial oxygen loss (ROL) from root can make their rhizospheric micro-environments under oxidation condition. Recently, the roles of root aerencyma and ROL of wetland plants in their heavy metal uptake and tolerance have aroused great concern and a number of relevant researches have been conducted. This paper reviewed the research progress and some issues relating to characteristics of aerenchyma and ROL, the effects of aerenchyma and ROL on heavy metal uptake and tolerance, and the rhizospheric micro-environments of wetland plants. Finally, this paper also discussed the trends of future researches on aerenchyma, ROL, heavy metal uptake and tolerance of wetland plants. It suggested that in order to prove further the role of aerenchyma and ROL of wetland plant to heavy metal tolerance, the research on the environmentally chemical behaviors of heavy metals in rhizosphere of wetland plants should be emphasized, and more attention should be paid to the development and application of advanced research methods and tools.