The present invention relates to a method for preparing a porous organic-inorganic hybrid, which comprises gelling a reaction mixture containing a metal precursor, a water-soluble additive and water or water-containing organic solvent at a gelling temperature of 30° C.˜100° C. to obtain an organogel-containing solution having a viscosity of 2 to 50,000 (cps), subsequently ageing the solution at said gelling temperature under stirring; and subsequently heating the organogel-containing solution at a temperature between said gelling temperature and 250° C. to crystallize the solution.According to the method for preparation of the present invention, it is possible to commercially practice the present invention since the reaction can be carried out in water or a water-containing organic solvent at an ambient pressure or a slightly raised pressure under a reflux condition, as well as it is possible to mass-produce a porous organic-inorganic hybrid having a high crystallinity and a large surface even in a high mol ratio of 1:1˜1:30 of solvent to metal.