Abstract: With the methods of literature，comparative analysis，mathematical statistics，video viewing and others，the tactial rhythm was studied for the 17 athletes who have the best results within 1：29：00 in the 20km walking race of the Rio Olympic Games or the best time of the season within 1：29：00 . The results showed that the overall athletic competences of the 17 athletes have not been shown out；the rhythm change and speed of the first eight athletes were different in each section，the difference was obvious in the second half，and the rhythm of the whole process was dominated by the positive rhythm；the rhythm and speed suitable for individual have important impacts on competition results；champion LIU Hong had the biggest chang amplitude and dispersion degree of speed for whole course, while the No. eight had the smallest ones，the chang amplitude and dispersion degree of speed negatively correlated with the ranking results；for 17 players in the game, there were alternating，forward or backward state，alternate position rhythm was more conducive to ″teamwork″ and was used by most players.

Key words: the Rio Olympic Games, women, 20 km walking race, tactical rhythm, speed rhythm, position rhythm