This paper presents the pattern visual evoked potential (PVEP) results and comparative study between the two groups of 65 normal infants at the age of 3, 6, 9, 12 months and 18 normal adults. The different pattern spatial frequency stimulations (74', 25', 6') were given to the infants and adults. In the infant group, the latencies of P1 components of PVEP delayed significantly and amplitudes of PVEP decreased significantly between 74' and 6' spatial frequency with the spatial frequency of stimulation increasing. In the same spatial frequency stimulation, when 3 months infant group was compared with the 6, 9, 12 months infant and adult groups, the latencies of N1 and P1 waves showed significant difference, but no difference was found in the amplitudes of P1 wave. Our results might indicate that the visual function expressed by low, medium, and high spatial frequency in infants from 6 to 12 months could reach the level in adults, and in 3 months infants, not maturely develop.