This investigation is a study on the cytoarchitectonics of the wall of the cerebral sulcus in the temporal pole area of 159 Korean brains (97 brains of the male, from the newborn to the age of 85, 62 brains of the female , from the newborm to the age of 60). The thickness of the total cortex and each corticallayer, the relative neuron density and the relative glia density in C100μ)3 of each cortical layer and the relative total neuron and glia densities of the cortex were observed and the results were summerized as follows: 1. The mean thickness of the cortex in the 0~1 year group was 1. 62~ 1. 83mm, which was 72.7% of the adult cortex thickness and increased to 2. 11~2. 22 mm in the 2~5 year group which was 90% of the adult and thereafter it increased to the adult mean thickness in the 11~15 year group, and thereafter it was relatively stable. The mean thickness of the adult cortex was 2. 37mm. The thickness of the cortex increased gradually as the brain weight increased to 1. 400 gms and thereafter it was relatively stable. 2. The highest neuron density in the 0-1 year group decreased rapidly to the adult mean value in the 1115 year group and thereafter it was reatively stable. The mean neuron density of the adult cortex was 383. As the relationship between the neuron density and the brain weight, it was highest in 300-500 gms stage of brain weight and decreased rapidly in the 700-899 gms stage and decreased gradually to the adult mean value in the 1.200-1. 299 gms stage and thereafter it decreased slowly. 3. The highest glia density was observed in the 0-1 year group but it was lower than the neuron density in the same age group and it decreased very rapidly to the minimum value in the 2-5 year group and following this it gradually increased. In the 500699 gms stage of the brain weight the mean glia density was highest and deceased very rapidly to the minimum value in the 1.100-1. 199 gms stage, thereafter it increased graduay as the brain afieght increased. 4. The neuron density and glia density had no sexual difference and left •right difference.