Objective:Mental development dysonotogenesis is a rather complicated and at the same time insufficiently researched issue concerning children with special needs. This is one of the most urgent problems of modern special and age psychology, since the definition of the type of dysontogenesis for different mental disorders is necessary for a special psychologist, teacher and speech therapist, first of all, in order to understand the mechanisms of formation of cognitive, emotional and speech disorders and their place in the defect structure. Objective methods of psycho-pedagogical dilant diagnostics to present date do not exist. Therefore, the purpose of the study was to develop an algorithm for chronopsychological prognosing of the mental development dysonotogenesis.Method:An experimental method of chronometric test using an electronic chronoscope; methods of mathematical statistics (descriptive statistics, percentile statistics, methods of averages, comparison of mean values using the Student’s t-test.).Results:Comparing the quadratic deviations of σ (quality index of an individual clock) in subjects of a representative sample with the level of their psychometric intelligence (IQ), a simple dependence was obtained: the smaller σ, the higher the IQ of personality. The quality of an individual’s watch, like the clock itself, is congenital, so the quality score (σ) should be considered as one of the indicators of the basic intellectual potential (“factor g”) of the individual. The mathematical analysis of the study results showed that oligophrenia and children with mental development delay have a different deviation from the analogue of the “qualitative” clock. In children with mental development delay, there is a deviation from the accuracy of given intervals of time reproduction only from 0.03 to 0.05. In mentally retarded children it is from 0.05 to 0.1 and not less. It enables to objectively predict the form of the manifestation of the preschool children mental development dysontogenesis, which is an important diagnostic criterion for assessing the mental status of a child.Conclusion:The choice of psychological and temporal indicators of the mental development dysontogenesis course allowed to develop an algorithm of chronopsychological prediction of the mental disorder manifestation form, the essence of which is that the subjective time unit of the individual acts as a central factor, which allows predicting the dysonotogenesis manifestation form, that is, to determine whether the diagnosis is mental retardation or delayed mental development. In the case of mental retardation, the unit itself is stable, i.e. does not change during the life of the reproduction of different periods of time. With mental retardation, it changes in a jumping manner, depending on the mental defect depth. In other words, due to the jump in the oligophrenic psyche there is no proper structure of the direct experience of time. Therefore it becomes possible to assume that in such groups of children there is a difficulty in the assimilation of time concepts, the difficulty in shaping the imagination of the metric properties of time, and the violation of the orientation in the past and the future in oligophrenic children is largely determined by the deviation from the analogue of “qualitative” watches. The consistent implementation of the stages of our chronopsychological prognosing algorithm, which could be relatively easy to be adapted for use in special pedagogy, would provide the opportunity to achieve the greatest effect in conducting a psychological and pedagogical examination of children with mental development dysontogenesis.