As a preliminary study for the development of electrical stimulation strategy of artificial retina, we set up a method for the reconstruction of input intensity variation from retinal ganglion cell (RGC) responses. In order to estimate light intensity variation, we used an optimal linear filter trained from given stimulus intensity variation and multiple single unit spike trains from RGCs. By applying ON/OFF stimulation repetitively, the type of a specific RGC was determined. In the case of ON/OFF stimulus in which temporal variation is slow, very successful reconstruction was achieved and the correlation coefficient was as high as 0.8. The reconstruction of Gaussian and binary random stimulus was also presented.