Triuret has been successfully synthesized by the reaction of urea with dimethyl carbonate (DMC) under mild conditions in the presence of potassium methoxide as a catalyst. It has been fully characterized by FT-IR, 1H-NMR, 13C-NMR, and MS. Effects of the catalyst, the molar ratio of starting materials, and the reaction time on the obtained product were examined in detail. It was found that when n (urea) : n (DMC)=1.2 : 1, 6 h, and 0.8% catalyst, the yield of triuret can reach 98.1%. Especially, this novel procedure is reported for the first time and has many significant advantages such as easy and clean synthesis, simple work up, and high yields.