A NEW series of 2,4-disubstituted phthalazin-1(2H)-one derivatives were synthesized via nucleophilic attach of N-2 of phthalazin-1(2H)-one derivatives on different monosuccharides. Synthesis of phthalazinone nucleosides were very effective as antimicrobial. Also the phthalazinone moiety can be used in synthesis of reactive nucleosides and dyes that were chemically bonded with proteins and fibers respectively as afforded highly stability of dyestuff wool and cotton textiles. The structure of the prepared compounds was elucidated by physical and spectral data like FT-IR, 1 H-and 13 C-NMR.