Abstract: An efficient and practical method for the synthesis of 6-(2-(3,3-dimethyloxiran-2-yl)ethyl)naphthalene-1,4-dione by utilizing epoxidation of 6-(4-methylpent-3-en-1-yl)naphthalene-1,4-dione withperacetic acid as an oxidant was described. The structure of the product was determined by ¹H-NMR, FT-IR and GC-MS analyses. Effects of solvent, reaction time, temperature and the ratio of the starting material, oxidant and sodium bicarbonate on conversion rate of the starting material and yield of the product were examined, and the optimal conditions were determined as follows: the molar ratio of 6-(4-methylpent-3-en-1-yl)naphthalene-1,4-dione/peracetic acid/sodium bicarbonate was 1:3:1.2,chloroform was used as the solvent, reaction temperature was 30 ℃, and reaction time was 5 h. The yield of 6-(2-(3,3-dimethyloxiran-2-yl)ethyl)naphthalene-1,4-dione reached 90.7% at aforesaid conditions.