The article is devoted to the problems of diagnosing the formation of speech processes in preschoolers. The article deals with the diagnostics of phonemic processes formation in children with general level 3 speech development. A thorough analysis of the works of domestic and foreign scientists on the formation of phonetic processes in children of senior preschool wreath is carried out. The analysis of the system of diagnostics on logopedic classes using computer technologies is given. The modern diagnostics of the state of formation of the phonemic perception processes has been developed and outlined. The state of speech in older preschool children has been studied in stages. Provision of means and methods of diagnostics of the child's speech in preschool educational institutions is analyzed. The problem of computer support on the example of the Logopedic Center "Development" of the city of Nikolaev is outlined. The necessity and importance of timely and qualitative diagnostics of the state of formation of phonemic processes in preschool children with general underdevelopment of the level III speech are substantiated. The main directions of actual improvement of the diagnostic process are identified and outlined. The main trends and directions of the process of diagnostics of the child's speech with the help of innovative computer technologies are separated and outlined. The model of diagnostics of phonemic processes formation is developed and tested, which includes the following criteria: – criterion I – formation of phonetic processes – Indicator 1 – phonemic analysis – Indicator 2 – the formation of phonemic synthesis – Indicator 3 – the formation of phonemic representations – criterion II – stability of attention – Indicator 1 – Stability of attention – Indicator 2 – focus – Indicator 3 – switching attention