Social security system of Iran has confronted various difficulties in the field of social welfare, most of which return back to performance of pension funds. Hence, the World Bank suggests moving toward integration of funds for social security system of Iran. Considering problems derived from multiplicity of pension funds in Iran, the aim of the present study is to investigate different aspects of pension funds integration as a corrective mechanism. Hence, firstly we proceeded on concept, necessity and competent authority of pension funds integration, and then in another section the most important barriers and difficulties of integration of them have been explained. Findings of the present study revealed that although integration of pension funds of Iran is a necessary issue, which can decrease most of the difficulties in the field of insurance, achievement of the issue confronts various difficulties and problems, the most important of which are legal and structural barriers. Elimination of the current barriers firstly requires legal solutions. However, since experience of social security of Iran has shown, mere legislation in the field cannot be fruitful, and support of senior managers of the country from pension funds is an indispensible necessity.