Proteins are core executors of biological activity inside cells, therefore, construction of protein-protein interaction network is so important to interpret protein function and decipher the secret of various cellular phenomena. Tandem affinity purification (TAP) is recent advance in technology made over past few years now enables the study of protein-protein interaction in vivo and the knowledge gathered from such methods will decipher the protein complexes network. Now, it is also a powerful tool available for proteomics research. This new technology will continue to be developed as it is now became extraordinary valuable to study protein-protein interaction.