Poly(4-vinylpyridine)-b-Poly(dimethylsiloxane) (P4VP-b-PDMS) copolymers have been synthesized by sequential anionic polymerization of 4VP and hexamethylcyclotrisiloxane at - 70-degrees-C. The initiator was sodium naphthenate. The solvent used during reactions has a very critical role in an homogeneous polymerization medium. A 1:1 pyridine/THF mixture was found to be the most suitable. The products were characterized by H-1-NMR spectroscopy, transmission electron microscopy (TEM) and differential scanning calorimetry (DSC) techniques. All the results indicated the formation of 4-vinylpyridine-siloxane block copolymers. Also, the P4VP blocks can be completely quaternized with methyl iodide as indicated by H-1-NMR and FTIR spectroscopies.