The 1-(2,3,4,6-tetra-O-acetyl-beta-D-galactopyranosyl)-3-aryl-5-benzyl (or substituted benzyl)-1,2,4-triazin-6(1H)-/ones or thiones were prepared via galactosidation of 3-aryl-5-benzyl (or substituted benzyl)-1,2,4-triazin-6(1H)-/ones or thiones with 2,3,4,6-tetra-O-acetyl-alpha-D-galactopyranosyl bromide. The structure of the new galactosyl derivatives was based on both spectroscopic and chemical evidences.