A FPGA based multichannel cortical stimulator system for cortical visual prosthesis was designed. devised for generating a sequence of electrical pulses for cortical stimulation. The simulator is composed of a FPGA and voltage/current converters. The FPGA comprises a spike generator to generate various electrical pulse sequences and some multiplexers to select signals. The prototype based on an Altera Cyclone EP1C6 FPGA with four channels is developed to perform the experimental evaluation. Two electrode chips ane put out of the left and right dura of cortex of a cat. The electrical stimulation is connected to the left one, while the visual electrically evoked potential (EEP) is recorded by the right one. The experimental results on cat's cortex show that the cortex can respond to the current stimulation.