Crosslinked amphoteric starches (CAS) with quaternary ammonium cationic and carboxymethyl anionic groups were prepared by a microwave radiation method. Their adsorption behavior for Cr(VI) was investigated. The results showed that high the degree of substitution (DS) of modified starch was favorable to the synthesis by the microwave heating and crosslinked amphoteric starches prepared with higher the adsorption capacity than by the drying reaction. The adsorption capacity increases with the increasing cationic groups and decreased with increasing degree of substitution of anionic groups. The adsorption capacity was found to follow the Langmuir isotherm.