The ordered mesoporous materials have been prepared from selected diblock copolymers, which allow the fabrication of mesoporous silica at room temperature with a short preparation time and generates materials with uniform pore structures. Selected MPEG-b-PDLLA block copolymers have been synthesized by ring-opening polymerization with systematic variation of the chain lengths of the resident hydrophilic and hydrophobic blocks. The size and shape of the micelles that spontaneously form in solution are then controlled by the characteristics of the block copolymer template. The formation mechanism of these nanoporous structures obtained by controlling the micelle size has been confirmed by TEM, solid state 29 Si NMR techniques. This work both proposes and verifies the formation mechanism of nanoporous structures in which the pore size and wall thickness are closely dependent on the size of hydrophobic cores and hydrophilic shells of the block copolymer templates.