Abstract: Surface modification of nanotitania was studied by using nanotitania as raw material and water as solvent.Effect of factors,such as kinds of modifiers,use level of modifier,mass fraction of milk,reaction temperature,and reaction time,on surface modification degree of nanotitania was investigated by wet method.Results showed that wetting property of nanotitania was improved obviously in organic solvent after nanotitania being modified by hexamethyl disilazane.And surface modification of nanotitania could be influenced by use level of hexamethyl disilazane,mass fraction of milk,reaction temperature,and reaction time.The better processing conditions were:mass fraction of hexamethyl disilazane was 15%,mass fraction of milk was 30%,reaction temperature was 90 ℃,and reaction time was 1 h.Surface modification effect of nanotitania was measured by wetting property of nanotitania.<BR>