Polyurethane (PU) is consist of alternating soft segment and hard segment. The soft segment provides elastomeric character such as low transition temperature and flexibility. On the other hand, the hard segment forms dimensional stability. PU has formed micro phase separated morphologies due to the thermodynamic incompatibility of soft segment and hard segment. In this study, we synthesized PU by polycarbonyl diol (PCD), hexamethylene diisocyanate (IPDI) and monodicarbinol terminated polydimethylsiloxane. Siloxane chain using as soft segment has many unique properties, for example resistance to high and low temperature and excellent flexibility. Rheological properties were investigated by rheometer.