The study aimed at investigation into the first step of language acquisition by Russian children and the imitation process as a possible mechanism of mastering the language through the sounds specific for their native language. On the basis of spectrographic, phonetic, and listener's analysis of the sounds infants, the beginning of shaping of the phonologic system in Russian language, was shown. It was shown that, during imitation of mother's voice, children acquire articulation skills and sound utterances approximating a phoneme category of the native language. The data obtained indicate that interaction between mother and child fulfills the function of learning transmitting a language data on the tongue trame.