Acetylcholine localization was studied immunohistochemically in neurons of the area 17 and 18 in the hamster visual cortex using anti-acetylcholine serum. It was found that the Ach-labeled cells are nonpyramidal neurons primarily and a few pyramidal neurons also exist. These neurons were found to be distributed in layer Ⅱ～Ⅵ, concentrated in the layer Ⅱ～Ⅳ. The neurons in the area 17 having greater density are arranged to form a columns perpendicular to the surface of the visual cortex and the neurons in the area 18 having smaller density are distributed dispersely. In the different layers of the visual cortex, the type of stained neurons has variation with that the majority of these neurons were bipolar in layer Ⅱ, Ⅳ and the multipolar cells in the other layers.