Abstract: Dodecanol was selected out as surface modifier for silica surface modification.Influences of the factors,such as dodecanol′s dosage,modification time,and modification temperature etc.on modification effect were discussed.Through single factor experiment,the optimum process conditions were obtained as follows：dosage of dodecanol modifier was 30 mL,1 g paratoluenesulfonic acid,10 g SiO₂,20 mL secondary solvent xylene,modification time was 70 min,and modification temperature was 70 ℃.Under these conditions：settlement volume of product was 3.55 mL/g,activation degree was 92.85%,and capacity of oil absorption was 2.53 mL/g.In addition,hydrophobic property of product was very good.

Key words: dodecanol, modification, silica