A photosensitive epoxy resin was synthesized from bis(4-hydroxy -3-methoxy benzylidene) acetone and epichlorohydrin using solution polycondensation method. The prepared epoxy resin was characterized by UV, IR, H-1 NMR, and C-13 NMR spectroscopy. The thermal stability of the epoxy resin was assessed by thermogravimetric analysis. The glass transition temperature of the polymer was determined by differential scanning calorimetry. The photocrosslinking property and photopolymerizing ability of the epoxy resin were studied in film and solution state using UV spectroscopy. The effect of photo acid generator and sensitizer on photosensitivity of the resin was also investigated. (C) 2008 Wiley Periodicals, Inc. J Appl Polym Sci 111: 2340-2344, 2009