PURPOSE:To investigate the effect of the retinal ganglion cell on the origin of the scotopic threshold response(STR)of the cat and human electroretinogram. METHODS:An optic atrophy model was established in cats with retinal photocoagulation around the optic disc. The STR and flash visual evoked potentials(FVEP)were recorded from 18 cases(24 eyes)of normal human,6 cases of the optic atrophy patients,6 cases of normal cats and 4 cases of retinal photocoagulating cats in 4, 8 and 16 weeks after retinal photocoagulation. In addition,ganglion cells were observated in 8 and 16 weeks after retinal photocoagulation using light and electron microscopes. RESULTS :The pathologic changes after retinal photocoagulation verify secondary atrophy of ganglion cells. STR was normal and FVEP was not recorded in cats of retinal photocoagulation and patients with optic atrophy. CONCLUSION :Retinal ganglion cell loss does not abolish the cat and human STR.There is no effect of ganglion cell on the origin of STR. （Chin J Ocul Fundus Dis,1997,13: 215-218 ）