This research was conducted with the aim of determining the relationship between the motivation of sports participation with leisure time physical activity among adolescents in Chalus city. The research method is a descriptive survey according to the subject and objectives of the research. Data collection has been done in the field. It is also practical in terms of using the results. According to statistics and information provided by Iran Statistics Center in 2015, this number is equal to 18,245 people. The number of statistical sample was determined based on Morgan's table, which was equal to 385 people. Two library and field methods were used to collect data. The tools of this research include four demographic questionnaires including personal information of first and second high school students, sports participation motivation questionnaire (PMQ), and leisure time physical activity questionnaire by Godin and Shepherd (1985) was Chi-square test and Spearman's correlation were used at a significance level of 0.05. The results showed that there is a positive and significant relationship between the motivation of teenage students to participate in physical activity and the level of leisure time physical activity in Chalus city. But the motivation of teenage students to participate in physical activity and the level of physical activity during leisure time of girls and boys of Chalus city did not differ. It seems that by improving to increase the motivation of teenage students to participate in physical activity and lead to an increase in the activity level of teenage physical activity students.