Provided is a method and apparatus for extracting phase information and reconstructing a volumetric image. A method of extracting phase information and reconstructing a volumetric image may include measuring an intensity image of light that passes a sample using an optical signal measurement device; and extracting optical phase information of the sample by applying Kramers-Kronig relations to the measured intensity image. A volumetric image may be reconstructed based on phase information extraction of the sample and the phase information.