Communication is important for organisms living in nature. Quorum sensing system (QS) are intercellular communication systems that promote the sociality of microbes. Microorganisms could promote cell-to-cell cooperation and population density to adapt to the changing environment through QS-mediated regulation that is dependent on the secretion and the detection of signal molecules (or called autoinducers). QS system is also discovered in acidophiles, a microorganism that is widely used in the bioleaching industry and can live in an acidic environment. An example is the LuxI/R-like QS system (AfeI/R) that has been reported in the chemoautotrophic species of the genus Acidithiobacillus. In this chapter, we will introduce the types and distribution of the QS system, and the biological function and regulatory mechanism of QS in acidophiles. We will also discuss the potential ecological function of QS system and the application value of the QS system in the control and regulation of the bioleaching process in the related industries and acid mine damage.