The most important question in this article is what is the obstacles in iran that causes iran could not attract foreign direct investment? The basic hypothesis in this research is that legal, economic & political obstacles and compose with each other cause that iran could not attract foreign direct investment. legal, economic & political obstacles and compose with each other consider as independent variable and unsuccesfull in attracting of foreign direct investment consider as dependent variable. The time range of this research is from triumph of Islamic reveloution of iran to now. The methodology is based on examination of statistics, documents & viewpoint of researchers. Information is provided at first with use of library resources and secondly between valid documents of responsible organization and centers. It should be notified that because of relation between writer's job and topic of article, try that finding of research founded on applied experiments. Finding of research shows that unsuccesfull in attracting of foreign direct investment is concluded from legal, economic & political obstacles and compose with each other. So at present we can not rely only one of these obstacles as most important factor. In this research obstacles of foreign direct investment is recognized and afterwards for every it's soloution is suggested.