Introduction - The article describes the possibilities of using the phenomenon of individual biological year (circannual biological rhythm) as a basis for working out the methods of developing the motor abilities of schoolchildren according to the individual educational trajectory. A fact-finding observation (motor abilities testing) of schoolchildren in the 1-11th grades was carried out, a total of 1678 people. The test results were processed by decomposing empirical rays into a theoretical Fourier series. The characteristics of the dynamic series were calculated. It was proved that empirical fluctuations of test results by months from the date of birth, statistically reliably described by the formula of the fifth harmonic of the Fourier series. An algorithm for developing an individual educational trajectory for the development of motor abilities on the basis of the individual biological year of schoolchildren has been compiled. It is concluded that this algorithm in its basis has a universal character and can be applied in the system of general education (primary, basic, secondary), secondary vocational education (technical schools and colleges) and higher education (baccalaureate, specialist) in the process of teaching physical education. The aim of the study - is to design an individual educational trajectory based on the individual biological year. Methodology and organization of the study - the study of the concept of the biological year to ensure the development of motorabilities of schoolchildren. Results of the study and their discussion - an algorithm for developing an individual educational trajectory was constructed. Conclusions - "Individual biological year" is defined by us as a socio-biological phenomenon, which in its implementation has a synergistic nature, and in the pedagogical aspect is the basis of "individual educational trajectory" development of motor abilities of schoolchildren