The results of longitudinal study, based on the corpus data of an oral personal discourse of 4-6 - year - old children are presented in the paper. The data were collected by means of the innovative methodological approach The Methodology for Simulation a Peer Conversation (MeSPeC) . During the analysis, a distribution of passages of different discourse genres and their developmental changes along the four wawes were estimated. In the paper, the fundamental patterns of the oral discourse acquisition are discussed with the main focus on the genre variability changes along the children’s age.