At present, researches on the treatment of abnormal receptor protein diseases are developing continuously, G protein coupled receptors (GPCRs) are the main targets in these researches. GPCRs is a large class in the family of receptor proteins, its special structure is opening up a new idea for the diagnosis and treatment of diseases. Calcium-sensing receptor (CaSR), a member of GPCRs, was discovered in 1993. It has been studied in many tissues and organs. Researcher found that the changes of expression quantity of CaSR associated with certain diseases development. In addition, CaSR related reagents have been carried on preliminary clinical attempt in some diseases. This paper has comprehensive narrated CaSR, its relationship with diseases and potential clinical application.