Pyrazolines are one of the heterocyclic compounds with very important biological activites. In this view, it was proposed to synthesize some novel pyrazolines from chalcones. Here the synthesis of pyrazolines using piperazine chalcones and phenyl hydrazine under basic condition in presence of ethanol. The structures of synthesized were assigned on the basis of elemental analysis, IR and 1H NMR spectroscopy data. These compounds were screened for their anti-bacterial activity.