Abstract: To explore the optimum adsorption conditions of methylene blue by sugar beet pulp(SBP), the beet pulp was saponified and modified to obtain saponification modified sugar beet pulp(SSBP) and citric acid esterification modified sugar beet pulp(CDSBP), respectively. The optimum adsorption conditions and kinetics of methylene blue by SSBP and CDSBP were explored. The results showed that the optimum adsorption conditions of SSBP were as follows: the concentration of methylene blue was 300 mg/L, the solution pH value was 7, the adsorption temperature was 60℃, the adsorption time was 60 min, and the adsorption capacity was 277.75 mg/g. The optimum adsorption conditions of CDSBP were as follows: the concentration of methylene blue was 400 mg/L, the solution pH value was 8, the adsorption temperature was 60℃, the adsorption time was 90 min, and the maximum adsorption capacity was 322.4 mg/g. In contrast, the adsorption performance of CDSBP was better. The adsorption process of methylene blue by SSBP and CDSBP conformed to the pseudo-second-order kinetic model and the Langmuir model, and the main mechanism might be ion exchange. The key chemical groups such as hydroxyl and carbonyl groups in SSBP and CDSBP played an important role in improving the adsorption performance. The number of these functional groups could be significantly increased by modification treatment, so that the adsorption performance was greatly improved.