In this study, a detailed annotation of human defensin was performed and also found out the best interactors of defensin peptide from human using STRING database. The selected peptide showed best associations with its various isoforms such as neutrophil defensins, α-defensins and β-defensins. A phylogenetic tree was also reconstructed to analyse the evolutionary relationships of human defensin with its selected isoforms. The human neutrophil defensin including all neutrophil defensins appeared in a separate clade. But a great divergence has been observed in case of β-defensins because they all did not fall in a single clade and showing more distantly relationships with α-defensins and with each other as well. In future, this study will provide scientists an ease to explore novel associations of human defensins with its various isoforms and other homologs