alpha-Butyl-omega-N,N-dihydroxyethylaminopropylpolydimethylsiloxane, a monotelechelic polydimethylsiloxane with a diol-end group, which is used to prepare polyurethane-polysiloxane graft polymer, was successfully synthesized. The preparation included five steps, which are hydroxyl protection, alkylation, anionic ring-opening polymerization, hydrosilylation, and deprotection. The products were characterized by FTIR, GC, LC-MS, H-1 NMR, and elemental analysis. The results showed that each step was successfully carried out and the targeted products were synthesized in all cases. (C) 2008 Wiley Periodicals, Inc.