Cation-pi interaction plays an important role in protein structure stability. In our present study, we have analyzed influence of cation-pi interaction in structural stability of metalloproteins. VVe observed that cation-pi interactions of Arg/Lys-pi interactions might have a significant role in the global conformational stability of metalloproteins. Though Trp residues have lower natural occurrence (1.76%) in proteins but it's shown the higher energetic contribution in metalloproteins. The preference of Arg interactions with Tyr and Trp is higher. Arg/Lys-pi interactions in metalloproteins will be useful for further structural studies and functional involvement on these proteins. © 2015 Scientific Publishers. All Rights Reserved.