In order to examine the inhibition effect of other heavy metal ions on the removal of heavy metal ions by crab shell in aqueous solution, 10 heavy metal ions (Cr3+, Cd2+, Ni2+, Zn2+, Hg2+, Cu2+, Mn2+, Fe2+, Fe3+, Pb2+) were used as single heavy metal ions and mixed heavy metal ions, respectively. In single heavy metal ions, Pb2+, Cr3+, Cu2+ were well removed by crab shell, however, Cd2+, Ni2+, Zn2+, Mn2+ were not. The heavy metal removal increased as the increase of covalent index (Xm2r), and the relationship classified heavy metal ions as 2 heavy metal groups (Fe3+, Fe2+, Cu2+, Cr3+, Mn2+, Ni2+, Zn2+ group and Pb2+, Hg2+, Cd2+ group). In mixed heavy heavy metal ions, the removals of Fe2+, Fe3+, Pb2+, Cu2+ as 0.49 mmol/g, regardless of the existence of other heavy metal ions, were similar to the result of single heavy metal ions experiment. The removals of Mn2+, Cd2+, Ni2+ decreased as the existence of other heavy metal ions, however, the removal of Zn2+, Cr3+, Hg2+ increased.