Abstract: The invention relates to a triazole derivative with an activity inhibiting glycine transporter and for use as a pharmaceutical drug, and a novel triazole derivative. The inventive triazole derivative has an excellent activity inhibiting glycine transporter and is useful as a therapeutic agent of dementia, schizophrenia, cognitive disorders, or cognitive disorders involved in various diseases such as Alzheimer disease, Parkinson's disease, or Huntington disease or the like, or spasm involved in diseases such as nerve degenerative diseases and cerebrovascular disorders, or the like. Particularly, the pharmaceutical drug is useful for the amelioration of learning disability of dementia and the like.