working memory is the comprehensive cognitive system that embedded attentional and memorical mechanisms and therefore can be used in systematic research of cognitive problems. The aim of this study was to investigate the predictive role of working memory capacity and executive functions (shifting, inhibition and updating) for Obsessive Compulsive Disorder. We selected 164 student (90 male and 74 female) from university of Tehran with random sampling method and they completed Maudsley Obsessional – Compulsive Inventory (Hodgson & Rachman, 1977), the Digit Backward Span Task (workingmemory capacity), Forward Span task (Short Term Memory), Stroop (inhibition, Spreen & Strauss, 1998), Set- Switching Task (shifting, Rogers & Monsell, 1995) and Keep Track Task (updating, Martinez, et al., 2011). Data analyzing used regression showed working memory and executive function totally predict considerable amount (67 percent) of obsessive compulsive predisposition. Therefore it can be concluding, obsessive people have crucial weakness in storage, monitoring and executive cognitive function (in general attention control) and we can use training in these functions as treatment strategies.