The metalloregulatory protein is the metal-specific binding protein in microorganisms that tightly regulates the intake, efflux, and storage of the metal ions through the regulatory mechanism of transcriptional repression or activation, which is particularly important for the maintaining of suitable metal concentration and homeostasis. In this review, the regulatory mechanism and topological structure are summarized within the current seven major families of metalloregulatory proteins, and the structural feature and metal-ligand coordination geometry of metal-binding domain are also introduced in detail. Based on the metal-ligand coordination geometry, the mechanisms are discussed for the metal selectivity of metalloregulatory proteins. In addition, the applications of metalloregulatory proteins in metal-ion detection and adsorption are also introduced, which not only broadens the research and application areas of metalloregulatory proteins, but also exploits new direction for the bioinorganic chemistry research.