OBJECTIVE To investigate the difference in color pattern reversal visual evoked potential (CPR-VEP)between primary open angle glaucoma (POAG) and primary angle closure glaucoma (PACG) patients. METHODS Vision Monitor visual electrophysiograph made by Metro Vision Inc. in France was used to record CPR-VEP in 17 eyes of 12 POAG patients, 56 eyes of 41 PACG patients, and 26 eyes of 13 age-equivalent normal persons at an ascending series of temporal frequency (1, 2, 4, 8, 16, and 32 Hz) and color stimulation (black/white, red/green, and blue/yellow). P(100) wave amplitudes and latencies of these patients were compared respectively with those of the normal group. RESULTS With black/white stimulation, the P(100) wave amplitudes were reduced with the increase of temporal frequency in the 3 groups. The P(100) wave latencies were extended with the increase of temporal frequency with different color stimulations. The P(100) amplitudes were PACG group > NC group > POAG group and black/white > blue/yellow > red/green. The P(100) wave latencies in the POAG group and the PACG group were extended compared with the NC group, but there was no significant difference between PACG group and POAG group. CONCLUSIONS CPR-VEP P(100) amplitudes in the PACG group and POAG group have their own characteristics. The P(100) amplitude of PACG is higher, and POAG is lower than normal. The P(100) wave latencies of PACG and POAG are extended.