Abstract: Biochar has been widely used as adsorbent to treat wastewater polluted with heavy metals and phosphorus polluted water, which has become a front-line hot spot in the field of environmental science. Submerged plants, abundant in quantity and vast in availability can be utilized as raw materials of biochar. However, little has been reported about researches on characteristics of Cr⁶⁺ and phosphorus removal by the biochar. Three common submerged plants (Potamogeton crispus, Vallisneria natans and Ceratophyllum demersum) were taken and pyrolyzed at 350, 450 and 600℃ into biochars, which were tested for exploration of effects of initial pH and equilibrium time on Cr⁶⁺ and phosphorus adsorption by the biochars. Results show that acid conditions facilitated Cr⁶⁺ and phosphorus adsorptions by the biochars, J350 (biochar prepared out of Ceratophyllum demersum at 350℃) and Y350 (biochar prepared out of Potamogeton crispus at 350℃) was the highest in Cr⁶⁺ and phosphorus adsorption capacity, being 0.094 2 mmol·g^-1 at pH 4 and 0.338 1 mmol·g^-1 at pH 6, respectively. The adsorption of two substances followed the pseudo-second-order model, which indicates that the adsorption process was dominated with chemical adsorption. The biochars derived from submerged plants were rich in carboxyl, hydroxyl and other oxygen containing functional groups. All of the biochars were 8 in pH_pzc, except for K450 (biochar prepareed out of Vallisneria natans at 450℃), which was only 6. Having adsorbed Cr⁶⁺ and phosphorus, the biochars had rougher surface with apparent folds and bright spot, and their contents of Cr⁶⁺ and phosphate increased significantly. Because of their unique physical and chemical structure, the biochars derived from submerged plants can be prepared into porous carbon for use in pollutant adsorption and other fields.