This study was conducted with the aim of determining the variaty of some stress electrocardiography index on athletes in Hai Phong city. The subjects were divided into two groups: experimental group included 60 athletes and control group included 30 pupils with age from 14 to 15 years old. All subjects were record electrocardiography (EGG) before and after physical' stress, some EGG indices would be analysed. The results showed that, after physical stress, the heart rate of athletes group was higher than that of control group. Before and after physical stress, the R wave amplitude in V 5 lead of athletes group was higher than that of contrQI group. The shortening systole time of athletes group was more than that of control group. The shortening diastole time of athletes group was less than that of control group. The rate of right brand block, left brand block, ST elevation, ST despression, T wave flat, T wave tall and T wave negative of athletes group were lower than that of control group pupils.