The adsorption separation and thermodynamic behavior of 2,4-diaminotoluene and 2,6-diaminotoluene on macropore acrylic acid weak acid cation exchange resin(D151 resin),which was selected from ten resins,were investigated.The adsorption isotherms of 2,4-diaminotoluene and 2,6-diaminotoluene were measured.The result showed that the adsorption isotherm curves of 2,4-diaminotoluene and 2,6-diaminotoluene on D151 resin fitted Freundlich adsorption isotherm better than Langmuir with the correlation coefficient larger than 0.99.The study of thermodynamics showed that when the initial concentration of 2,4-diaminotoluene were 60~80 g/L within 293~313 K,the adsorption ΔH was-4.3490~-5.7558 kJ/mol,ΔG was-0.2911~-1.0346 kJ/mol,ΔS was-12.965~-16.150 J/(mol·K);and when the initial concentration of 2,6-diaminotoluene were 60~80 g/L within 293~313 K,adsorption ΔH was-2.9645~-3.6054 kJ/mol,ΔG was-0.1610~-0.6384 kJ/mol,and ΔS was-7.939~-11.005 J/(mol·K).The results show that the concentration of 2,6-diaminotoluene can be enriched from 20% to 99.93%,and 2,4-diaminotoluene can be increased from 80% to 99.42% with the dynamic adsorption separation.