Abstract In this study, hypoxia inducible factor-1α (HIF-1α) and hypoxia inducible factor-1β (HIF-1β) from small abalone Haliotis diversicolor were cloned. The cDNA of H. diversicolor HIF-1α (HdHIF-1α) is 2833bp encoding a protein of 711aa and H. diversicolor HIF-1β (HdHIF-1β) is 1919bp encoding a protein of 590aa. Similar to other species' HIF-1, HdHIF-1 has one basic helix–loop–helix (bHLH) domain and two Per-Arnt-Sim (PAS) domains, and HdHIF-1α has a oxygen-dependent degradation domain (ODDD) with two proline hydroxylation motifs and a C-terminal transactivation domain (C-TAD) with an asparagine hydroxylation motif. Under normoxic conditions, HdHIF-1α and HdHIF-1β mRNAs were constitutively present in all examined tissues. Under hypoxia (2.0mg/L DO at 25°C) stress, HdHIF-1α expression was up-regulated in gills at 4h, 24h and 96h, and in hemocytes at 24h and 96h, while HdHIF-1β remained relatively constant. Under thermal stress (31°C), HdHIF-1α expression was significantly increased in gills at 4h, and hemocytes at 0h and 4h, while HdHIF-1β expression still remained relatively constant. These results suggested that HIF-1α may play an important role in adaption to poor environment in H. diversicolor.