The dynamics of accumulation of polyphenols in two hawthorn species – Crataegus pentagyna and C. caucasica has been investigated. It has been established that the course of the changes of various polyphenols during growth and fruit development in both species occurs in the same manner. Polyphenol content in the initial stages of fruit growth and development is gradually increased up to a maximum in completely formed fruit and then begins to decrease gradually, and their quantity reaches a minimum in overripe fruit. The changes of amounts of the main components of polyphenols during growth and fruit development follow the same path as the total amount of polyphenols. It has been established that along with a change of total polyphenol content its individual components, in particular anthocyanins also varies.