Keywords: sprint, speed of reaction, crouching start From the position, that the term .sprint. suggests running with maximal intensity from the start to the final, the authors consider, that the start reaction of the sprinter should be considered as a condition for maximal quick acceleration and reaching maximal velocity of running.In the study the time of start reaction in different sprint events of 952 athletes, 834 of which male and 118 - female, participated in the world championships in athletics during the last 10 years have been analyzed. It is determined that in 100 meters men show significantly better start reaction than women, while at the longer sprint events the best of the women show a start reaction that is close to the men.s. The already established tendency that the increasing of the distance the start reaction timing is worsening has been confirmed as for the men as well as for the women.Considering the contemporary technical conditions for giving the start commands and the start signal, the start reaction is not affected by the lane number of the sprinters. Criteria for valuation of the start reaction of the different events, which corresponds to the real abilities of the competitors in the sprint events, have been developed on the basis of the studied data and could be used in the control of their start abilities.