BACKGROUND: Adipose stem cell (ASC) therapy has been tested as a new option for the treatment of type 2 diabetes (T2D). Our previous transcriptome sequencing analysis showed that the adrenergic α2 receptor (Adra2α) was highly expressed in ASCs from T2D mice compared to healthy controls. This study aims to explore the role of Adra2α on the characterization and therapeutic function of ASCs. METHODS: Clonidine (an Adra2α agonist) or si-RNA was used to observe Adra2α on ASCs proliferation, migration, growth factors (HGF, TGF-β1 and VEGF) expression and secretion. T2D mice were treated with non-treated control or Adra2α knockdown T2D ASCs (namely NC ASCs or KD ASCs). Mice glucose levels, insulin sensitivity and other metabolic indicators were measured and compared. RESULTS: Treatment of ASCs with Clonidine reduced the proliferation, migration, and growth factors expression and secretion of ASCs, while Adra2α knocking down ASCs showed opposite effects. This translated in vivo when T2D + KD ASCs could improve hyperglycemia and insulin resistance, reduce fat content in adipose tissues and livers, suppress body inflammation, and increase pancreatic β cell mass in T2D mice compared to NC ASCs. CONCLUSIONS: Adra2α plays a critical role in regulating the proliferation, migration, and expression of growth factors of ASCs. Suppression of Adra2α expression in T2D ASCs restored/improved their therapeutic effects.