As a Lewis weak acid, the hydration and acid dissociation mechanisms of B(OH)(3) are still unclear. In present letter, we calculated the optimized structure, stability and Raman spectra for micro-hydrated clusters of B(OH)(3) with DFT in both gaseous and aqueous phase at B3LYP/aug-cc-pVDZ level. The stepwise micro-hydration process of B(OH)(3) were described in detailed. The micro-hydration process and Raman spectrum study indicate that the axial hydration is a "trigger" for B(OH)(3) dissociation. (C) 2015 Elsevier B.V. All rights reserved.