This paper investigates the social relationship and life quality. The paper analyzes a secondary data form a survey is conducted by Iranian Student’s Polling Agency, ISPA, about favorable or optimal life among University students. The sample is consisted of 20670 people in different parts of Tehran.

Results show 59 percent of respondents have average life quality and social capital and its dimensions social trust and social participation had the highest score among others. The levels of these three variables were different and significant in types of life quality.

After analysis of findings through calculation of path analysis coefficient, the results indicate that among variables influencing on the social capital, average life quality with 85 correlation co-efficiency, has the highest influence. Results indicate that average life quality increases solidarity and relation realm of individuals and it can result into the trust and finally, all these factors increase and reinforce social capital.