Objective To improve the surface hydrophilicity of PET materials. Methods In this paper, highly hydrophilic PET materials were prepared by blending with SnCl2 and then grafting amination-modified nano-silica on the surface of the blended film. The surface properties of PET materials were characterized by static contact angle measurement, Fourier transformed infrared spec- troscopy and atomic force microscopy. Results The results showed that amination-modified nano-silica was successfully grafted on the surface of the SnCl2 / PET blended materials. When the content of SnCl2 was 0. 3% in PET materials, the surface contact angle of blending membrane dropped from 98° to 74. 5°. The surface contact angle of PET materials dropped from 74. 5° to 7. 8° after the blending membrane was grafted with amination-modified nano-silica for 20 h, and the hydrophilicity was increased dramatically. The surface contact angle of PET materials increased from 7. 8° to 34. 9°after the grafted membrane was soaked in distilled water for 10 d. Conclusion The surface hydrophilicity of PET materials was improved greatly by blending with SnCl2 and then grafting amina- tion-modified nano-silica.