Various substituted ketones (R1-R10) were condensed with Thiophene aldehyde in the presence of ethanol to get various chalcones (P1-P10). Resulted chalcones were then made to react with hydrazine hydrate and hydrazine hydrate derivatives to get the various Pyrazoline compounds (PP1-PP10 and AA1-AA10). The structures of these compounds are established on the basis of elemental analysis and spectral analysis (UV, IR and NMR etc.). The synthesized compounds were evaluated for antimicrobial activity. All these compounds were found effective against almost all microorganisms.