Silica nanoparticles with different sizes (ranging from 10 nm to 104 nm) and size distributions were synthesized by semi-batch and semi-batch/batch methods of the Stober process. Then the amorphous silica with different surface areas (ranging from 30m2/g to 400m2/g) and pores (ranging from 3 nm to 33 nm) were obtained by various aging treatments and drying methods of the synthesized colloidal silica sol. The aging treatment resulted in the monodispersed pore distribution and decreased BET surface area of silica. The high-humidity drying method led to the mesoporous silica with uniform pores and decreased small pores. As the silica was obtained by the arrangement of silica nanoparticles, the pore diameter and pore distribution of mesoporous silica were directly related to the size and distribution of nanoparticles. Furthermore, this study offered a new thought for the synthesis of other mesoporous materials with uniform pore distributions.