To study the effects of root structure on the ability of oxygen release from the root systems of plants(expressed by root oxygen release rate and sensibility of root oxygen release rate to dynamic water level), four different wetland plants were used(Acorus calamus Linn, Thalia dealbata, Typha orientalis Presl , Phragmites australis).The root oxygen release rates in five different water levels were measured using titanium citrate buffer. Standard deviation was also used to illustrate the sensibility to dynamic water level of different wetland plants. In addition, root porosity was measured by pycnometer method and root structure was observed by microscope. The results showed that the root oxygen release rate of these wetland plants decreased in the following order as a whole: Typha> Phragmites> Thalia> Acorus. The sensibility of root oxygen release rate to dynamic water level decreased in the following order: Typha> Phragmites> Acorus > Thalia. Moreover, it was found that more developed Aerenchyma and less oxygen barrier may have positive relationship with the ability of root oxygen release. The more sensitive to the release rate of the plant root system, the more sensitive to the change of water level.