A novel low-temperature regenerative hydroxy-functionalized hyper branched polyamine adsorbent (0.160H-HBPA) for CO, capture was readily prepared using glutaraldehyde to cross-link amino-terminated hyperbranched polymers (HBP) and functionalized with glycidol, followed by the reduction of the imino groups of 0.160H-HBPA to alkyl aminos using NaBH4. Here, the HBP has been prepared through the one-pot reaction between pentaethylenehexamine and methyl acrylate. The as-prepared 0.160H-HBPA adsorbent showed a high adsorption capacity (4.05 mmol/g) for CO, (concentration, 10%) in the presence of water at 25 degrees C, and the alkyl amino utilization efficiency reached 73%. More importantly, the CO2-adsorbed 0.160H-HBPA showed excellent regenerative performance at low temperatures (85 degrees C, under pure CO, gas) due to the introduced hydroxyl that can cooperatively adsorb CO, via the amino groups to form stable carbamic acid. This process suppressed the formation of open-chain urea and cyclic urea and could overcome the disadvantages of high regeneration temperatures (>= 90 degrees C, under pure inert gas) of CO2-adsorbed traditional solid amine adsorbents.