Acryloyl chloride (AC) was radiation grafted from 30% solution of monomer in toluene onto polydiethyleneglycol-bis-allylcarbonate (CR-39) by their simultaneous gamma-iradiation. The grafting process was more efficient at dose rate of 4.4 kGy/h as compared with 0.4 kGy/h, and grafting values of 15-18% were achieved at 2.2-5.5 kGy. Subsequent immobilization of disperse red 1 (DR1) onto the grafted polymer was carried out from 0.02 M solution of this dye in dichloroethane, and the immobilized DR1 yield increased with the grafted polyAC value. Surfaces of the starting and modifed CR-39 were characterized with the FTIR-ATR spectroscopy and atomic force microscopy. An essential difference in chemical structure and topography of the CR-39 surface before and after the DR1 immobilization has been shown. The colourless plates of CR-39 became red after the DR1 immobilization, and the color intensity increased with the dye content. Changes in visible absorption spectra of the immobilzed DR1 caused by the photoinduced trans-cis isomerization of this dye were discussed.