Several interesting papers related with the problems of mathematical modelling in connection with a study of aging and longevity have been published recently in "Advances of Gerontology"; see, for example, [1-4, 10, 11]. Following the main idea of these papers we consider here some approaches for construction of statistical models used today in survival analysis and reliability, and which can be used in demography, gerontology and carcinogenesis studies. We expose the so called dynamic regression models, which are well adapted for studies of survival in dynamic environments.