In this study, citation analysis of theses had been done through 627 theses in University of Tabriz during period of 2005-2009. In these 627 theses we have 44,488 citations and we investigated those thesis based on publication type (such as web, journal, book and etc), language and the date they had been examined. These differences were shown by change of time and years. In addition citations were investigated by half-life characteristics too.