This paper studied the influence of end-capping reagents including 3-triethoxysilylpropylamine (KH550) and hydroxyethyl acrylate (HEA) on the properties of polyurethane dispersions (WPU). Polyurethane dispersions were prepared by pre-polymer method and the structure of polyurethane backbone was characterized by FTIR. The influences of the dosage of KH550 and HEA on particle size and distribution, surface tension, viscosity and adhesion of dispersions were investigated. The particle size and distribution of WPU were increased with increase of the dosage of KH550 but the viscosity decreased. The introduction of KH550 deduced the surface tension obviously but HEA had a little influence on the surface tension. With increase of the dosage of HEA, the particle size and distribution of WPU decreased but the viscosity increased. The adhesion of the two modified end-capping reagents on the PA and PET packaging film was excellent. The introduction of KH550 can improve the adhesion of WPU on films and adjust the viscosity of dispersions.