The research aims to identify the effect of using a water bag on the level of (dynamic balance) for the handball junior under study and the level of (defensive movements) for the handball junior under study, according to the nature of the research problem and to achieve its goals and test its hypotheses, the researchers followed the experimental method using the experimental design for one group by following the pre- and post-measurement of the sample under study.The percentage improvement rates between the pre- and post-measurements for the group using water bag training ranged between (19.49%: 24.95%), which indicates the effect of the program based on using water bag training in improving the physical and skill variables for the group using water bag training which indicates the effect of the program based on using water bag training in improving the physical and skill variables for the group using water bag training.