Micro/nano-scale noble metal (Ag, Au, Pt) particles decorated 3D porous nickel electrodes for hydrogen evolution reaction (HER) in alkaline electrolyte are fabricated via galvanostatic electrodeposition technique. The developed electrodes are characterized by field emission scanning electron microscopy and electrochemical measurements including Tafel polarization curves, cyclic voltammetry and electrochemical impedance spectroscopy. It is clearly shown that the enlarged real surface area due to 3D highly porous dendritic structure has greatly reinforced the electrocatalytic activity towards HER. Comparative analysis of electrodeposited Ag, Au and Pt particles decorated porous nickel electrodes for HER indicates that both intrinsic property and size of the noble metal particles can lead to distinct catalytic activities. Both nano-scale Au and Pt particles have further reinforcement effect towards HER, whereas micro-scale Ag particles exhibits reverse effect. As an effective 3D hydrogen evolution cathode, nano-scale Pt particles decorated 3D porous nickel electrode demonstrates the highest catalytic activity with an extremely low overpotential of -0.045 V for hydrogen production, a considerable exchange current density of 9.47 mA cm-2 at 25 oC and high durability in long-term electrolysis, which are attributed to the intrinsic catalytic property and the extremely small size of Pt particles.