Mesoporous silicas have been prepared using poly (ethylene glycol)-b-poly (propylene glycol)-b-poly (ethylene glycol) with average molecular weight of 8400 and 5800 as directed structure agent under neutral condition in the presence of methanol. X-ray diffraction experiment indicated that samples are mesoporous silicas with certain ordered structural pore. Thermogracimetric and differential thermal analyses (TGA/DTA) measurement showed two exothermic peaks in the DTA curve, the second peak proved that there is strong interaction between silica framework and organic template.