The urgency of the research is determined by the need to ensure the quality of higher education an essential factor of which is development of the internal assessment system for educational activities at universities. The aim of the article is validation of the model of development of the internal assessment system for educational activities at universities which is aimed at providing the management with immediate, objective and reliable information on the state and development of the educational process and the processes related to it, whether intermediate and final results correspond to the set goals and regulatory requirements. The leading research methods were teacher modeling and instructional design, theoretical analysis and review of educational practices in the field of quality assessment at a higher education institution, as well as mathematical methods of statistics, which allowed to comprehensively investigate the effectiveness of the suggested model based on the analysis of the dynamics of the key indicators of education quality. The article describes theoretical concepts which determine the characteristics of the model of development of the internal assessment system for educational activities at the university; its main components-the goal, principles, the objects for assessment and entities of assessment, the content and technology of assessment-are revealed; and it also highlights peculiarities of development of the internal quality assessment system at the university in relation to the external environment requirements and etc. The article can be of practical use when modernizing the quality assessment system at universities, when developing projects and programs on improving education quality assessment systems.