Kinetics and mechanism of oxidation of 1,4-butanediamine by a Ag(III) complex were studied spectrophotometrically in alkaline medium at constant ion strength. The reaction shows first order with respect to the Ag(III) complex and 1,4-butanediamine respectively. The second order rate constant, k′, increased with the increasing in [OH⁻], and decreased with the increasing in [IO₄⁻]. A plausible mechanism was proposed from the kinetics study. The rate equations derived from the mechanism can explain all experimental phenomena. The activation parameters were calculated.