The mesoporous molecular sieves MCM-41 were prepared using room tempera-ture ionic liquid (RTIL) synthesized in laboratory and cethytrimethylammonium bromide (CTAB) as compound templates for the first time. They were prepared under low aging temperature and short aging time. Via characterizing by XRD and nitrogen adsorption instrument, MCM-41 synthesized by this new method exhibited good crystal structure and narrow pore distribution. The following pre-40 h and calcined at 540 ℃. It is found that the acidified MCM-41 improves its activity as catalyst over the unmodified ones.