---

Background and purpose: This study was conducted to determine Relationship between participation motivation and Social – Economic Status of youth in Tehran. Method: This study was cross-sectional and done by questionnaire. The analyses were based on data that collected from sports clubs in four Tehran regions (North, South, East and West), (n= 130) young people (65 male, 65 female) were selected randomly and completed the participation motivation questionnaire (PMQ) and socioeconomic status questionnaire. Result: results of Pearson’s correlation showed that there was a significant positive relationship between motivational component subscales of participation motivation in sport and socioeconomic status in young people (p ≤ 0.05). Conclusion: The present study determined there was a significant relationship between income statues, economic-class, parents’ education level and sport participation motivation.  The finding revealed that the families with high-and middle- economic class and income have a greater incentive to engage in physical activity. The education level of parents, especially fathers play an important role in encouraging their children to participate in physical activities.