An improved synthesis of 8-mercaptomethone by utilizing sodium polysulfide instead of the H2S was developed. An L9 orthogonal array of the Taguchi method was implemented to investigate the effects of experimental conditions to prepare 8-mercaptomethone according to yields. The optimal conditions were determined by using Na2S4, H2O to react with pulegone accelerated by adding the Dowex® 50WX4 under conventional heating for 12h. In comparison with conventional methods, the prominent features of this procedure are experimental simplicity, without toxic H2S and the use of water as a green solvent