Article is devoted to the issues of symbolic mediation and diagnostic of time perception in sport. Distinction between iconic and symbolic mediation is discussed. Evidences of effective implementation of symbolic mediation in sport are examined. Means of optimization of sportsmen and sportswomen training by the instrumentality of symbol are considered. The results of time perception diagnostic of Russian synchronized swimmers are described. It was shown that sportswomen are greatly varied in accuracy and stability of reproduction of long (2–5 sec) and estimation of short (less than 250 ms) time intervals, which were filled with different contents – ticks of metronome, persistent sound, pressuring the button and etc. The improvement of individual characteristics of time perception is an important psychological resource of sports achievements increase.