objective: The aim of the present study is to find the effect of a slow running on static and dynamic balance training to students with Down syndrome Methods: The statistical sample consisted of 24 children with Down syndrome (mean age 19.35+3.5, Height 157.33+12, Weight 63.92+27.49) randomly divided into two groups of 12 subjects in the experimental group and control group. There were 12 sessions for 45 minutes with slow  exercise on treadmill which was considered for the experimental group . Stork balance test was used to assess the static balance and walking from heel to toe test was used to assess the dynamic balance   Results: The results showed that the difference between static and dynamic balance before and after exercise was significant. Conclusion: The use of slow running on the treadmill can be used as a way to improve the dynamic and static balance in children with Down syndrome.