In this study, it is aimed to review the effects of 8 week plyometric exercises on certain physiological parameters and freestyle swimming performance of swimmers of age 10-11 who practice swimming with a licence in city of Van. Study group has been created by 24 male volunteer swimmers who practice swimming with a licence in city of Van. 24 volunteer athletes aged 10-11, who are licenced swimmers for two years and who exercise regularly 5 days a week have been selected for the study. The athletes are randomly divided into experimental and control groups of 12. Throughout the study, in addition to swimming exercises, experimental group is scheduled to 3 days a week plyometric exercise program. Control group is not given any additional exercise except from the swimming exercises. It is seen that the obtained data does not show normal distribution and non-parametric tests of Mann Whitney U and Wilcoxon Test are used for data analysis. Significance level is taken as p<0,05. As per obtained data, pretest and post test data of male swimmers of experimental group show that horizontal and vertical leaps, anaerobic power, 30m sprint, hand grip right and left, 25 and 50 m freestyle swimming parameters showed statistical significant difference; whereas for control group, weight, height, body mass index, anaerobic power and right and left hand grip force parameters showed statistical significant difference (p<0,05). When the pretest and posttests of experimental and control groups are compared, only vertical leap parameter showed significant difference in favor of the experimental group (p<0,05) and for the other parameters, no statistical significant difference is seen (p>0,05). As a result, it is seen that the 8 week plyometric exercise has a significant effect on vertical leap and even though not statistically significant, it is pondered that it has a positive effect on freestyle swimming duration of experimental group, compared to that of control group.