The signal pathway for light‐induced expression of c‐fos and the neuropeptide somatostatin (SS) in rat retinal cells was investigated. Flashing light induced c‐fos and SS mRNA in the inner nuclear layer and the ganglion cell layer. As both c‐fos and SS genes have a cyclic AMP response element (CRE) in their promoters, CRE‐binding protein (CREB) phosphorylation in retinal cells was examined with a phospho‐CREB‐specific antibody. Both flashing light and administration of the L‐type Ca2+ channel activator Bay K 8644 induced phosphorylation of CREB in the nuclei of the amacrine cells and the ganglion cells where c‐fos/SS mRNAs were expressed. These cells could be double‐stained with anti‐calmodulin kinase II (anti‐CaM kinase II) monoclonal antibody and phospho‐CREB‐specific polyclonal antiserum after Bay K 8644 administration, indicating the colocalization of phosphorylated CREB at Ser133 and CaM kinase II in the neural retina.