Two types of mesoporous Si-MCM-41 materials were synthesized via a cationic surfactant template method using different Si-precursors. The materials obtained were characterized by FTIR, XRD, BET, TEM and 29Si MAS-NMR techniques. When fumed silica was used as Si precursor, a Si-MCM-41-I solid with wormhole-like pore topologies was obtained. However, when tetraethylorthosilicate (TEOS) was used as Si precursor, a mesoporous Si-MCM-41-II solid with hexagonal arranges and a long-range ordered structure could be obtained. These two kinds of mesoporous materials had a uniform pore size distribution with an average pore diameter within 2.3-2.8 nm. Rather weak Lewis acid sites were formed on both the Si-MCM-41 samples prepared by the two methods.