Аннотация:The article presents a comparative analysis of the study of the mnemic abilities of younger schoolchildren with delayed mental development (100 students) and younger schoolchildren with a normal rate of mental development (105 students). The research methodology is based on the method of unfolding mnemonic activity (V. D. Shadrikova, L. V. Cheremoshkina). Experimental study included a pilot study, an ascertaining experiment and a longitudinal study, analysis of gender differences in mnemonic abilities of younger schoolchildren with different rates of mental development. It is revealed that the structure of mnemonic abilities of younger schoolchildren with delayed mental development is underdeveloped, in which the operating mechanisms are in an early stage of formation. The effect of inability to copy the previously memorized material by children with delayed mental development is also discussed in the paper.