With the development of technological approaches, the perturbations of biological information in gene, mRNA, proteins, and metabolites have been gathered to broaden the cognition of synthesis processes during lactation. While omics, the series of application including genomics, transcriptomics, proteomics, and metabolomics, are mostly preferred and conducted in the investigation of lactation especially the milk protein. These new technological approaches provide a complete view of the molecular regulation pathways and make it possible to systematically investigate the lactation. The aim of this chapter is to comprehensively review the advances in knowledge regarding the great progress in milk protein synthesis as well as lactation physiology and pathology mainly in dairy cows obtained from omics technologies, meanwhile the milk proteins as well as their attributes are illustrated.