To provide a decoration method excellent in friction resistance while holding the metal color of metal colloid particles by a combination of the metal colloid particles and a gloss stabilizing layer, a decoration article, and a nail beautifying agent.

The decoration method includes a process for forming a metal gloss layer by coating a base material with a metal gloss agent (A) containing the metal colloid particles (a1) and a solvent (a2) and a process for forming the gloss stabilizing layer by coating the metal gloss layer with a gloss stabilizing agent (B) containing a solvent (b2) non-compatible with or not dissolving the metal colloid particles (a1) and transparent resin (b1) dissolved in the solvent (b2).