The photoelectron spectra of Au − (H 2 O) 1,2 , Au2-(D 2 O) 1–4 , and AuOH − have been measured. The anionic complexes, Au − (H 2 O) 1,2 and Au2-(D 2 O) 1–4 , were characterized as Au − and Au2-, which are respectively solvated by water molecules. The stepwise spectral shifts between adjacent size species have been quantified. The photoelectron spectrum of AuOH − exhibits considerable vibrational structure. Based on our assignment of its spectrum, the adiabatic electron affinity of AuOH was determined to be 1.771±0.015eV.