To provide a hologram recording photosensitive compsn. and a hologram recording medium which are chemically stable and have high sensitivity for a wide wavelength region and excellent resolution, diffraction efficiency, transparency, light resistance and heat resistance, and to provide a production method of a hologram by using the medium.

This compsn. consists of a polymer compd. containing a polysiloxane compd. part in the side chain, a compd. having polymerizable ethylene type unsatd. bonds, and a photopolymn. initiator, and the compsn. gives ≥0.005 refractive index modulation degree by holographic exposure. The layer of the compsn. is formed on a base material to obtain a hologram recording medium. The hologram recording medium is hologram-exposed and then applied with light or heat to produce a volumetric phase type hologram.