Thiamine-HCl in a trimolar NaOH solution with equimolar glycine evolved H_2S and gradually precipitated a cryatalline product of mp. 115-117℃ (decomp). The release of H_2S from thiamine reached 65% of the theoretical value and the remaining thiamine was recovered to 21.8% of the initial value after 85 hours, while glycine was recovered to 96%. Thiamine can be resynthesized from the reaction-product by saturation of H_2S in its acetic acid solution. Therefore, the product seemed to be a desulfurized compound from the thiol-form of thiamine and its chemical structure will be discussed in the other report (Kurata, et al.).