Submicrosized porous hollow silica spheres with a diameter of 350 nm and a shell thickness of approximately 10 nm were synthesized by a hydrothermal method using PMMA hollow particles as template. Through the hydrolysis of TEOS, a continuous and uniform coating of SiO2 was deposited over the surface of PMMA cores to form the core-shell structures. After calcining to remove the template, a pure hollow silica structure with holes in the shells was obtained. The as-prepared hollow products were characterized with TEM, SEM, EDS, BET and FT-IR. Its large surface area and hollow morphology will make this new material a promising agent for the applications of catalysts, controlled drug delivery and etc.