The aim of the study is to investigate university students' the level of social capital and the factors affecting their social capital accumulation. University students' level of social capital (online and offline) is both affected by and happens though social media due to the rapid developments in mobile technologies. The data for this article is drawn from a larger research TUBITAK supported project. The project employed both quantitative and qualitative research methods. Some of the quantitative data was used for this article. There were 2., 3. and 4. grade students of 12 different Turkish state universities located in different parts of Turkey. The total number of the students involved in the study was 2253. The data was gathered by a demographic data collection form and 7 other scales developed for the project mentioned above. The scales were Likert type. Their reliability and dimensions are explained in detail in method section of the study. The data was subjected to stepwise regression analysis. The analysis of the data shows that; the university students' bonding social capital level is high as expected from a close family relationship is a dominant factor.