This experiment was conducted to evaluate its adsorption capacity of modified rice hull biochar. The biochar treated with 6M KOH solution was carbonized at 850℃. The maximum adsorption of NH4 + -N in aqueous solution and maximum removal rate were 0.65 mg g -1 and 56.3 %, respectively, in 6M KOH modified biochar. For palm biochar, the maximum adsorption and removal rate of PO4 - -P were 0.67 mg g -1 and 56.0%, respectively. It was observed that NH4 + -N in aqueous solution can be only adsorbed in rice hull modified biochar, and PO4 - -P in palm biochar. The sorption of NH4 + -N to 6M modified rice hull biochar was significantly fitted(p<0.001) by Langmuir isotherm model because it was observed that dimensionless constant (RL) was 0.39. The maximum adsorption amount (qm) and binding strength constant (b) were calculated as 0.65 mg g -1 and 0.057 mg L -1 , respectively. Furthermore, the leaching experiment of modified rice hull biochar mixed with soil need to be more elucidated in the future.