Waterborne polyurethanes (WPU) was synthesized using the polycaprolactone diol (PCL) as the polyol, and 4,4'-methylene dicyclohexyl diisocyanate (H₁₂MDI) as the isocyanate. The crosslinked WPU was obtained by the castor oil (CO) with the three functionalities. The synthesis was designed using PCL, castor oil and H12MDI as soft segment part, dimethylolbutanoic acid (DMBA) for the ionization, and trimethylamine (TEA) as neutralizer based on different molecular weight of prepolymer. Physical properties (the adhesion and biodegradation) as the bio-adhesives were studied through fourier-transform intrared spectroscopy (FT-IR), universal testing machine (UTM), contact angle, field emission-scanning electron microscopy (FE-SEM), degradingenzyme systems based on the different molecular weight of waterborne polyurethanes.