Telomerase is composed of the catalytic subunit TERT (Telomerase reverse transcriptase),RNA subunit TERC (Telomerase RNA component) and other telomerase associated proteins. These two compartments with other telomerase subunits can assemble a holoenzyme, which maintain the length of telomeres. Telomerase plays important roles in cell senescence and tumor formation. The molecular mechanisms of the regulation of telomerase are very complicated. These processes comprise the regulation of transcription, post-transcription, post-translation and subcellular localization. Trafficking and assemble of TERT and TERC, as well as recruitment to telomeres, are also involved in this process. Here we review the regulation mechanism of telomerase from these aspects, and aim to laid a foundation for telomerase associated research and the drug targeting the telomerase.