Purpose: The purpose of this research was to compare the effect of eight weeks of exercises based on NASM principles in land and water on the kyphosis angle of 15-18 year old students in Kermanshah city. Materials and methods: In this semi-experimental study, 45 non-athlet male students of the second grade of highschools in Kermanshah city, with hyperkyphosis more than 45 degrees, with an average age of 16±0.74 years, average weight of 60±0.5 kg and average height of 175 ± 0.30 cm were purposefully selected and randomly divided into three groups (exercises in water=15), (exercises on land=15) and (control=15). The exercise program in the experimental groups was conducted for 8 weeks, three sessions a week and each session lasted 60 minutes. The spinal mouse device was used to measure hyperkyphosis. The data were analyzed using 3*2 ANOVA and paired t test tests. Findings: The results showed that there is a significant difference in the kyphosis angle between the three groups of exercise in water, exercise on land and control (p<0.05). So that in the variable of hyperkyphosis, there was a significant decrease in the scores of the water exercise group from the pre-test (46.52) to the post-test (36.60), the dry exercise from the pre-test (46.81) to the post-test (28.28). 40). Conclusion: According to the results of this research, it is recommended to therapists and correctional movement specialists, considering that NASM exercises in water have had a greater effect on reducing the complications of hyperkyphosis in students, to prioritize these exercises as corrective exercises for hyperkyphosis and upper cruciate syndrome.