During postnatal development, activity of monoamine oxidase B in human brain structures increases, while activity of Cu,Zn-dependent SOD decreases with compensatory increase in catalase activity and ceruloplasmin content. Under these conditions, the resistance of the pontobulbar structures and thalamus to oxidative stress decreases at the age of 1-12 years and returned to the prenatal level during adolescence. The increase in catalase activity is most pronounced in structures of the forebrain (cortex and neostriatum), cerebellum, and hypothalamus; it is accompanied by ontogenetic increase in oxidative stress resistance, which is maximum at the age of 12-21 years. The maintenance of resistance to oxidative stress (depends on monoamine oxidase B) can be considered as an important condition of structural and functional maturation of cerebral structures during the postnatal ontogeny.