A novel series of 1-{N(1E)-substitutedcarbamimidoyl}3-{N-[(E)-substitutedmethylidene]carbamimidoyl}thiourea(VIa-e) were synthesized in this laboratory. 1-{N(1E)substitutedcarbamimidoyl}3-{N-[(E)-substitutedmethylidene]-carbamimidoylthiourea(VIa-ewere synthesized by the reaction of1-(N-carbamimidoyl)-3-{N-(E)-substitutedcarbamidoyl}thiourea(Va) with various aldehydes (IIa-e) in sulphuric acid in acetone-ethanol medium in 1:1 molar proportion for 20 minutes. The structures of all the synthesized compounds were justified on the basis of chemical characteristics, elemental analysis and spectral analysis.