Abstract: Telomeres are special DNA-protein complexes, which situated in the ends of eukaryotic chromosomes. Telomerase is a specialized ribonucleoprotein complex with reverse transcriptase activity that is capable of extending chromosome ends with specific telomeric DNA sequences by using a portion of its RNA component as a template and using 3’ telomere DNA as primers. It consists of two subunits TERC and TERT. The mtere-/- mice is one of the ideal model for study the functions of subunit TERC and related diseases. This article reviewed the applications of the model on study of tumor, aging, blood and reproduction.