Spontaneous emission and resonance fluorescence of an adatom adsorbed near a smail metallic particle are studied by means of the surface-dressed optical Bloch equations and the modified image theory. Spontaneous decay time and Lamb shift; resonance fluorescence spectrum, squeezing effects, and absorption lineqidth are discussed. The influences of size effects, distance between the adatom and particle, and fluctuation in the laser intensity on the optical property are analyzed.