Biochar have effects of adsorption on heavy metals and harmful organic material. We compared the adsorption of nitrogen and phosphorus by 5 different biochars produced from different water plants, Carex dimorpholepis Steud, Miscanthus sacchariflorus Benth, Phragmites communis, Typha orientalis and Zizania latifolia, compared to commercially activated carbon as a control. The adsorption capacities of biochars produced from different water plants were quantified. The adsorption characteristics of ammonium nitrogen, nitrate, nitrite and phosphorus by biochars were measured at 20°C. The results of this investigation were evaluated using the Freundlich and Langmuir adsorption isotherm equation. The maximum adsorption capacity of the ammonium nitrogen (determined by Langmuir isotherms) on the various biochars were in the order of Miscanthus sacchariflorus Benth > Phragmites communis > Carex dimorpholepis Steud > Typha orientalis > Zizania latifolia for all biochars tested. The maximum adsorption capacity of the phosphorus on the various biochars at different materials were in the order of Phragmites communis > Miscanthus sacchariflorus Benth > Typha orientalis > Carex dimorpholepis Steud > Zizania latifolia for all biochars tested.