Building an evolutionary model of human physical state necessitates information about his/her life periodization according to a criterion that correlates with vitality, health level, and work capacity. Therefore, the objective of our study was to analytically describe and determine the duration and most typical and characteristic determinants of periods of adaptation, normal vital activity, aging and death based on the function of the intensity of aging and death of the population of Ukraine in 2020. It reflects clearly and informatively its vitality, health level, and physical work capacity. Material and methods: Periodization was carried out according to the age and cause of death of 616,835 people, of which 305,755 were men and 311,080 were women based on the methods of statistical analysis, approximation, and systematization using the "STATISTICA 13.5" program. Results: The average life expectancy of men 66 years, women 76 years, and both sexes 71 years was differentiated into periods of adaptation, normal vital activity, aging and death, and their duration was determined, which constituted 5 – 41 – 20, 5 – 43 – 28, 5 – 42 – 24, respectively. The main cause of death during the period of adaptation is the manifestation of certain conditions that arise in the perinatal period, whereas during those of normal vital activity
and aging and death - external factors and diseases of the circulatory system, respectively. Conclusions: For the first time in 2020, an analytical model of the function of the intensity of aging and death was defined for the population of Ukraine, and according to the unified criterion of its speed change, life periods were differentiated and described by the superposition of exponents, their duration and the most typical and characteristic causes were determined.