The article, "morphosyntactic peculiarities of the speech of children with Down's syndrome", treats, important aspects of the study of two adjacent branches of linguistics, namely, psycholinguistics and neurolinguistics-Language development of the child accompanied by speech disorders, on the other hand, those morphosyntactic features that are specific to the Georgian language system, also appearing at the initial stage of the child's speech. Since communication disorders cover a wide spectrum, only children with Down's syndrome were selected for the study, because the genetic factor causing their speech disorder, unlike other disorders, is clearly known, and the systemic features of speech are defined in such a way that the results can be generalized, unlike other types of speech disorders, which have a more specific character. The research is related to the speech development of Georgian children with Down's syndrome, and the purpose of the research is to reveal the main patterns of the morphosyntactic features that are observable in the speech of children with Down's syndrome. Based on the specifics of the disorders, 9- and 10-years old children were selected for this research. Psychological observations have shown that the speech of a 10-year-old child with Down's syndrome corresponds to the speech of a child without a disorder, approximately 4-5 years old, the period when conscious speech begins. The main method of studying psychology is Observation. The most favorable material for studying a child's behaviour is given when it occurs in natural conditions. Thus, we will conduct the experiment in direct field conditions by using the "natural experiment" method. This way, can avoid us the bias of answers. I conducted research, with questionnaires and game-like interactive experimental tasks. I use the method used by Piaget called the "clinical method" (Piaget 1994). Questions and experimental tasks are designed to stimulate childrens responses in a direction that is in with the scope of my interest. The result of the research showed the morphosyntactic features characterising the speech of children with Down's syndrome. In particular, their speech is characterized by: (1) Very short sentences. As a rule, they perceive more than they express; (2) The development of speech is directly related to the development of fine motor skills of the hand; (3) their speech is characterized by focusing on one specific moment; (4) As a result of the research, the advantage of their visual memory was confirmed; (5) The phenomenon observed during the production of the past tense forms of the verb was hyperregulation; (6) They have a problem with understanding time and space in general; (7) The stages of their speech development correspond to the stages of cognitive development, of those children without impairment; and (8) Through experiments, it was determined that all children with Down's syndrome made typical mistakes. This fact will help psychologists and language therapists working with them to develop certain strategies, which will be focused on improving children's speech, and this, in turn, will help to improve their socialization.