Mesoporous silica particles with hexagonal or spherical structure were synthesized by a sol-gel method using tetraethoxysilane (TEOS) as a silica source, P123 (EO21PO70EO20) as a surfactant, and cetyltrimethylammonium bromide (CTMA Br) as the co-surfactant. And the experiment was carried out at the molar ratio of TEOS/P123/CTMABr (1:0.011:0.031). The effect of aging time on properties of mesoporous silica particles was studied and the obtained particles were also characterized by SEM, TEM, BET, TGA, and XRD. As a result, the particle size, surface area, and pore size of hexagonal mesoporous silica particles were similar to those of spherical mesoporous silica particles, and the pore size of all samples increased with aging time. N-2 adsorption/desorption isotherms for the mesoporous silica particles prepared by changing the aging time (0-14 h) were obtained and all the samples exhibited type IV isotherms. In addition, it was found that the difference between adsorption and desorption increased with aging time.