The boron-doped α-Ni(OH) 2 nanoflowers (B-α-Ni(OH) 2 ) with high specific surface area (400m 2 g −1 ) were synthesized by the one pot liquid-phase method using P123 (EO 20 PO 70 EO 20 ) as template and NaBH 4 as alkali and boron sources. The size of the B-α-Ni(OH) 2 nanoflowers is about 300nm and there are many porous. The 50nm nanoplates are the basic structure units of nanoflowers and thickness of the nanosheets is approximately 5nm. The content of B is about 15% among the Ni, B, O elements and boron exists mainly in the form of BO 2 − , which was confirmed by XPS characterization. B-α-Ni(OH) 2 nanoflowers exhibit a high specific capacitance of ~2296Fg −1 at a charge and discharge current density of 3Ag −1 with excellent cycling ability. The high specific capacitance and remarkable rate capability are promising for applications of B-α-Ni(OH) 2 nanostructures as advanced electrochemical capacitor materials with both high energy and cycling ability.