Abstract: Adsorption capability of methylene blue and basic fuchsin by jujube core as biological adsorbent was studied in simulated wastewater,firstly. Effects of the adsorbent size and content,adsorption time,p H and dye concentration on the adsorption performance to methylene blue and basic fuchsin in aqueous solution were studied on the basis of the results of single factor tests. Also adsorption mechanism was investigated by adsorption isotherm,adsorption kinetics and thermodynamics. The results showed that methylene blue and basic fuchsin in aqueous solution could be removed effectively by jujube core. When the initial p H was about 6and the dosage of jujube core was 8,10g/L respectively by adsorption of methylene blue and basic fuchsin,after 7 hours' treatment of 50mg/L two dyes wastewater using 60 mesh jujube core,the removal rate of two dyes was above 90%. The adsorption of methylene blue and basic fuchsin dye in aqueous solution by jujube core was a spontaneous adsorption,and the adsorption behavior was consistent with both the second order rate equation and Langmuir,Freundlich isotherm. The saturated adsorption capacity to methylene blue was22.94mg/g and that to basic fuchsin was 23.92mg/g by calculation. Jujube core was a promising biological material for cationic dye wastewater treatment.