The efficiency of chemically modified peanut shell (CMPS) on adsorbing cadmium ions was evaluated in this paper. The kinetic, isothermal and thermodynamic models were applied to study adsorption properties and characteristics in a batch system. The pH, adsorption time and initial concentrations were followed. The results indicated that under the indoor temperature (25℃), when pH was 8 and adsorption time was 40min, the adsorption capacity reached the maximum, 40.10mg/g. The kinetic adsorption was better described by pseudo-second-order rate model; Equilibrium experimental data were both fitted to linear Langmuir and Freundlich models, but Langmuir model provided a better coefficient of determination value; the theoretical maximum adsorption capacity calculated by Langmuir equation were 95.24, 105.26, 109.89mg/g at 283K, 298K and 308K respectively.