Abstract: <SPAN lang=EN-US style="FONT-SIZE: 10.5pt; FONT-FAMILY: "Times New Roman"; mso-bidi-font-size: 12.0pt; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体">Nano-sized KH-570 modified titanium dioxide (nano-TiO<SUB>2</SUB>) was in stiu prepared by sol-gel method,using butyl titanate (TBOT) as precursor,hydrochloric acid as catalyst and</SPAN><SPAN style="FONT-SIZE: 10.5pt; FONT-FAMILY: 宋体; mso-bidi-font-size: 12.0pt; mso-ascii-font-family: "Times New Roman"; mso-hansi-font-family: "Times New Roman"; mso-bidi-font-family: "Times New Roman"; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">γ</SPAN><SPAN lang=EN-US style="FONT-SIZE: 10.5pt; FONT-FAMILY: "Times New Roman"; mso-bidi-font-size: 12.0pt; mso-font-kerning: 1.0pt; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA; mso-fareast-font-family: 宋体">-methacryloxypropyl trimethoxy silane (KH-570) as modifying agent.Effects of the amount of KH-570 on surface modification of nano-TiO<SUB>2</SUB> were studied.Nano-TiO<SUB>2</SUB> was characterized by FT-IR,XRD,and particle size analyzer ect..Results showed that KH-570 was grafted onto the surface of nano-TiO<SUB>2</SUB> particles with anatase form;with the increase of amount of KH-570,grafting rate raised firstly and then reduced a little bit;when mass fraction of KH-570 to TBOT was 14.57%,grafting rate reached 25.6%;compared with unmodified nano-TiO<SUB>2</SUB>,average particle size of KH-570 modified nano-TiO<SUB>2 </SUB>decreased,its size distribution became narrow,and lipophilicity was improved apparently.</SPAN>