Mesoporous γ-Al2O3 nanofiber was prepared via a simple reverse precipitation route using Si-containing Al(OH)3 and HNO3 as raw materials. The resultant Si-containing mesoporous γ-Al2O3 nanofiber exhibited high surface area of 320 m2/g, large pore volume of 1.17 cm3/g and large pore size of 10.5 nm. The introduction of Si element remarkably enhanced the thermal stability of mesoporous γ-Al2O3. The as-prepared nanofiber could maintain relative high surface area(110 m2/g) and pore volume(0.73 cm3/g) up to 1100 °C. The effects of various experimental conditions, such as pH value, reaction temperature and aging temperature on the structural properties of the mesoporous γ-Al2O3 were also investigated.