Para hydroxyacetophenones react with different aldehydes of Para nitro benzaldehyde (Ia) ,Ortho nitro  benzaldehyde (Ib),4 hydroxy 3methoxy benzaldehyde (Ic) , 3, 4 dimethoxybenzaldehyde (Id)  in the presence of aqueous solution of potassium hydroxide and ethanol at room temperature to form 1,3 Diaryl-2-propane-1-ones or chalcones. The synthesized compounds were characterized by means of their IR spectral data. All the compounds were tested for their antibacterial activities by the cup plate method on E.coli ,Pseudomonasaeurgenosa, staphylococcus aeureous .Screening results shows that Id compound shows better antimicrobial activity against E.coli