The age dynamics of albino rat kidney cell proliferation in conditions of compensatory hypertrophy and influence of endogenous inhibitors on this process have been studied. The lack of influence of repeated injection of inhibitors on kidneys cell division of 1-month old rats has been shown, while the level of kidney proliferation of 3-month old rat and 12-month old rat decreased of about 50% and of 24-month old rat decreased of about 34%.