In recent decades, information systems outsourcing has become one of the most important problems of these systems management, and it is still at the stage of theoretical discussions regarding outsourcing (IS) activities. In this research, the backgrounds lead to the information systems outsourcing are mentioned first, in order to reveal more it's role in upgrading the sectors and services of these systems. Then, six basic factors in outsourcing decision making are taken into account including management, strategy, economic effects, technology, risk, and quality. Therefore, a decision making model is considered in Fuzzy environment using one of the multi criteria decision making methods; in other words analysis hierarchy process (AHP) approach. Due to the present ambiguities among the ideas of different experts, this model produces Fuzzy numerical values for comparing criteria, sub-criteria, and options so that the managers would be able to decide better about the outsourcing strategies for each of the desired information systems.