Abstract: Sixteen derivatives of BL-P1908 were synthesized by reaction of 2-aryl-1, 2, 4-triazine-3, 5-dione-6-carboxylic acid, or 2-phenyl-4-alkyl (aryl)-1, 2, 4-triazine-3, 5-dione-6-carboxylic acid with amoxicillin. All of them are new compounds. Their chemical structures were determined by elemental analysis, IR and ¹HNMR. Preliminary tests showed that all compounds have marked activities agairist standard G(+) and G(-) bacteria and five of them have certain characteristic of broad spectrum, but they have no activities against resistant strains S. aureus S₁, E coli C₁ and P. aeruginosa PS₁ isolated from clinic.