In this paper, a series of mesoporous silica particles with different pore diameters were fabricated using tetraethyl orthosilicate (TEOS) as the network precursor, hexadecyl trimethyl ammonium bromide (CTAB) as a structure directing agent and 1,3,5-Trimethylbenzene (TMB) as a pore enlarge reagent. Compared with SAXRD and BET, the PALS may not only show the mesoporous information but also provide the structure information of microporous. © (2009) Trans Tech Publications, Switzerland.