Abstract: Methyl, butyl, and benzyl ethers of thiosalicylic acid or dithiosalicylic acid were used as starting materials to undergo Horenstein and Pahlicke esterification reaction with β-diethylaminoethyl chloride and β-piperidinoethyl chloride in isopropyl alcohol respectively. Six basic ester hydrochlorides were thus prepared. These compounds were tested for therapeutic effect on schistosomiasis japonica in mice. No curative effect was observed.