The development of deuterium-incorporation method is eagerly desired. A solution of sodium deuteroxide in deuterium oxide (NaOD in D 2 O) was simply prepared by mixing D 2 O and t-BuONa. Subsequently, the t-BuOD layer, generated under conditions of the salting-out effect, was separate. The purity (volume of the contaminated t-BuOD as side-product) of the homemade NaOD in D 2 O was evaluated by 1 H NMR and Raman analyses. NaOD in D 2 O was used for the one-pot synthesis of mono-deuterated trans-stilbene (stilbene-d 1 ) in the aqueous Horner-Wadsworth-Emmons reaction. The present method can be widely applied to synthesize the various mono-deuterated stilbene derivatives with high deuterium content. Additionally, the obtained mono-deuterated stilbene derivatives could be successfully converted to various deuterated compounds.