Objective: In modem tennis, serve is very important, it is the only one which masters by yourself.It can not be restricted by the other side, and in the larger extent it can play out personal characteristics to control competitor, accordingly to create favorable conditions for their own offensive.Serve can mobilize more parts of the body.The range of motion is more, and the higher the degree of muscular coordination.Continuous smooth swing of the tennis serve process is the decisive factor in whether to issue strike.So, this experiment tested the surface electromyography to monitor the characteristics of the serve muscles in different heart rate level.It can provide the experimental basis for the quality of tennis serve when athletes were fatigue, and provide better tennis serve training methods for the coaches.Methods: players, tennis professional level 2 and above, are voluntary attend the test.They all come from Beijing Sport University.Test process is divided into two steps, the first step: Record the whole match process testing heart rate change.The second step: simulated heart rate increase stage, serve at every heart rate increased by 10 units, Players all wear EEG and Polar in the whole process.Results: with the increase of heart rate, the muscle of upper limb mobilization rate and contribution rate increase.core muscle and lower limb muscles have different way.Conclusion: The heart rate rising indicates the fatigue of players, Muscle mobilization and Serve power chain both are abnormal, the quality of the tennis serve discreased.