Objective: Our study aims to identify the differences in number of cation-pi and aromatic-aromatic interactions in a set of homodimers with known folding data (2S, 3SMI and 3SDI) towards having a deep insight in to their folding and binding. Methods: We have computed the contribution of cation-pi interactions for each protein in the data set using realistic electrostatics program CAPTURE. Aromatic- aromatic interactions of the proteins in the dataset are being identified using Protein Interactions Calculations (PIC) server. Results: The energetic contributions of residues involved in cation-pi interaction have been computed using CAPTURE, and the results are tabulated in Table 2. The result shows that maximum number of cation - pi interactions occurs in 3S than in 2S homodimers. Aromatic -aromatic interactions have been studied using PIC server. The result shows that maximum number of aromatic-aromatic interactions is again in 3S homodimers than in 2S. Conclusion: From the results obtained from our study, we find a number of energetically significant cation-pi interactions in the dataset. Analysis of cation-pi interaction energy revealed that there is stronger electrostatic energy than van der Waals energy. We compared the occurrence of six interaction pairs to understand which interaction pair is most preferred and found that preference of Arg-Tyr interactions is higher when compared to other interacting residues which suggest the importance of Arg-Tyr pair in the stability of proteins and we also find that the length of the protein has no significant effect on the number of interactions.