Hybrid emulsions containing inorganic nano particles were prepared by blending waterborne polyurethane (WPU) emulsions with colloidal silica. The hybrid emulsion and its film were characterized by TEM, laser particle analyzer, rheometer, ATR-FTIR, and TG respectively. The effects of silica content on the properties of the film were studied. The ATR-FTIR test results confirm that there is no chemical bond formation between silica particle and urethane polymer chains but hydrogen bonding. TEM and laser particle analyzer examinations showed that the average particle size of the hybrid emulsions increases and particle size distribution become wider with the increasing content of colloidal silica, the aggregation of silica particle in the hybrid emulsion would happen in the case of SiO2wt%>20%. The rheological analysis reveals that the apparent viscosity ( ) and pseudoplasticity of the hybrids are increased with increasing silica content. The property tests indicated that at about 20% silica content, the stability of the hybrid emulsion is good, its films show much better thermal stability, its water absorption was only 18. 94%(after 48h) also with higher performance in solvent resistance, tensile strength increases to 28.98MPa, pencil hardness is 2H,adhesion is 0 grade.