-The cha1cogenides of 4 -and 5 -component system viz. PbBi l _ x M0 2 _ x ' Te2_y Se2_z. Pb 2 Bi l _ x Mol_x·Te2_y Se2_z Pb2_Bi4_xTe3_y Se4_z and PbBi s _ x Te3_y Se4_z have been prepared at 900°C. These compounds crystallize into orthorhombic symmetry. The chemical compositions of these materials are confirmed by EDX. Resistivity studies showed these compounds are semiconducting.