Supercritical water oxidation is an innovative technology for wastewater treatment. Alkali metal acetate could be oxidized in supercritical water at greatly higher rate than that of acetic acid, which is a typical refractory intermediate in organic compound oxidation. Although heterogeneous oxidation catalyzed by in situ formed alkali metal titanate contributed into higher conversion rate, homogenous oxidation in supercritical phase was the main reaction pathway. Enhanced oxidation of alkali metal acetate has great potential to enable short and complete oxidations of refractory organic compounds.