Some new substituted thiadiazines containing galactose moiety were prepared by cyc1ization reaction of 3-aryl-4bromoacetylsydnones with 2,3,4,6-tetra-O-acetyl-beta-D-galactopyranosyl thiosemicarbazide using microwave-assisted method under solvent-tree conditions. The structure of obtained products was confmned by spectroscopic (IR, 1H and 13CNMR) methods and their inhibitory activities on some bacteria and fungi were estimated.