1. Thio-choline bromide was prepared by heating bromocholine bromide with 2-thio-uracil or 4-methyl-2-thio-uracil with water in a closed tube or pressure bottle at 150°C and 170°C. for two and five hours respectively. The compound is hygroscopic in nature, and is very soluble in both alcohol and water. It decomposes at 243°C. on heating. Its isoelectric point was found to be 7.00. 2. By heating with hydrobromic acid the compound is easily oxidized to its disulphide, which is a syrupy and less pronounced ionizable substance, in aqueous solution. 3. On treating an aqueous solution of this compound, with an excess of silver oxide, and neutrallizing with hydrobromic acid and heating on the steam bath, an insoluble white asbestos-like crystalline substance was formed. It appears to be the following formula: (Remark: Graphics omitted.) The compound is slightly soluble in alkaline solution. It decomposes at 214°C.