Hypoxia-inducible factor-1 (HIF-1), identified as one of the transcription factors, has been found to play an essential role in oxygen homeostasis. HIF-1 is a heterodimer composed of HIF-1 beta subunit and one of three subunits (Hif-1 alpha, Hif-2 alpha or Hif-3 alpha). The activation of Hif-1 alpha is closely associated with a variety of tumors and oncogenic pathways. Hif-1 alpha consists of DNA binding domain(DBD domain), dimerization domain and C-terminal regulatory domains, including two transactivation domains(TAD), an oxygen-dependent degradation(ODD) domain, and inhibitory domains.