Studies were made in order to prepare presensitized plates from poly (vinyl cinnamate), a photosensitive polymer, and zinc plates. Main results obtained are as follows:(1) A dark reaction of poly (vinyl cinnamate) in contact with a surface of zinc plates was not observed though the dark reaction in the same conditions had been reported by other authors, (2) Desensitization during storage was observed in the presensitized plate sensitized by some sensitizers. The phenomenon may be due to the evaporation of the sensitizers from a thin film of poly (vinyl cinnamate); therefore, sensitizers used for presensitized plates must be selected.(3) Coloration of poly (vinyl cinnamate) by phthalocyanine blue B pigment little affects the property of the photosensitive polymer.(4) After-exposure by a low-pressure mercury lamp (2537Å) must be made after development when the presensitized plate for relief printing is etched by Dow etch process for longer time than 5 minuites.(5) Poly (vinyl cinnamate) can be used as a resist for lithographic printing. It was concluded that presensitized plates for relief printing and lithographic printing can be made of poly (vinyl cinnamate) and zinc plates.