Abstract: The folate receptor is a membrane protein overexpressed in tumor cells.Two folate receptor isoforms have been identified in humans by the modern molecular biology, α and β.The type α receptor is frequently overexpressed in epithelial-lineaged tumors and the type β in nonepithelial-derived tumors.Both isoforms show a high affinity for folic acid.The folate receptor is overexpressed in approximately 100% of other ovarian carcinomas and a wide variety of other human cancers,including breast,cervical,colorectal and nasopharyngeal tumors,while being highly restricted in most normal tissues.The studies of folate receptor in the isoforms,structures,gene mapping,distribution,ligand and application in trmor nuclear medicine will be helpful in the early diagnosis and treatment of tumors.