2-(1-(4-hydroxy-2-oxo-2H-chromen-3-yl)ethylidene) hydrazinecarboxamide, 2-(1-(4-hydroxy-2-oxo-2H-chromen-3- yl)ethylidene) hydrazinecarbothioamide,4-hydroxy-3-(1-(2-hydroxyethylimino)ethyl)-2H-chromen-2-one and 4- hydroxy-3-(1-(2-mercaptoethylimino)ethyl)-2H-chromen-2-one were synthesized by condensation of semicarbazide, thiosemicarbazide, 2-aminoethanol and 2-aminothioethanolamine with 3-acetyl-4-hydroxy-2H-chromen-2-one. These Schiff bases were characterized by IR, 1HNMR, 13CNMR and mass spectral analysis. In vitro biological screening effects of the synthesized compounds were tested against the bacterial species Staphylococcus aureus, Escherichia coli, Salmonella typhi, and Bacillus subtilis by Agar cup method. Fungal species Aspergillus niger, Penicillium chrysogenum, Fusarium moneliforme and Aspergillus flavus were tested by the poison plate method