Changes in number and distribution fo retinal ganglion cells were studied after optic nerve crush in zebrafish (Brudrylanio rerio) with retinal wholemount. There were approximately 40, 000 to 56, 000 cells in he retinal ganglion cell layer. The density of ganglion cells was divided into aix classess and the area of ligh-est cell density (central area) was located at the temponal area to the optic disc in normal fish. At the early re-generation stages after optic nerve crush, the percentage of lost cells increased gradually. Cell density had fallen first in the central area. At the late regeneration stages, there was an approximately 20% loss of ganglion cells. During optic nerve regenenation. The results suggest that the loss of cells may undergo apoptosis racher the necrosis. A wave of cell loss started in the central area and spread progrevely further into periphery. The reason caused these charges may be due to tempotal interruption of optic nerve function, recovery from crush and the dbility to quickly regererate in optic nerve of the fish.