This study intended to discuss 12 weeks of tug of war training on elementary school student physical fitness and evaluated the benefit of tug of war training. The study aimed at the forth, fifth, and sixth grade students of Gao-liao primary School in Hualien County. The students were divided into two groups: experiment group and control group. The experiment group,19 people received tug of war training, 40 minutes, 4 times a week during 12 weeks and the control group, 19 people received none training. Both groups received physical fitness test before the experiment and after the experiment. The content of physical fitness includes:1.Body Mass Index;2.Stand jumping;3.One-minute sit up;4.Sit and reach;5. 800m jogging. After the experiment, the progress range was tested by two ways ANOVA. The α-level was set at .05. The result indicated that the elementary school students who received 12 weeks of tug of war training had significant progress in flexibility, muscle endurance, power, and cardiovascular except in body composition.