A series of silicone modified polyurethane(Si-PU) block polymers were synthesized from using polybutylene adipate (PBA), methane-4-4’-diisocyanate(MDI), 1,4–butanediol(BDO) and hydroxyl terminated polysiloxane(HO-PDMS). The effect of synthesis condition on the shear strength was investigated. The influnce of the content of HO-PDMS on the absorption properties of PU was tested. The structure of the synthetic products was characterized by Infrared Spectrum, the surface hydrophobicity was examined by surface contact angle and the scanning electron microscopy(SEM), respectively. The results showed that the silicone chain segments were incorporated into PU macromolecule. The shear strength firstly decreased slightly and then decressed greatly with increasing the HO-PDMS content. But the modified polyurethane had low surface energy, surface water contact was improved by 25°C, and the water resistance was also improved.