in modern societies, there are a lot of problems such as economic and environmental constraints due to our tradeoff between past and new technology goals, in power generation, transmission, distribution. To solve these problems, much researches have been done to use green and cheap energy sources like solar and wind powers. Therefore modern power system grid get more changes from conventional power system grid. So, designers consider these changes in details based upon intensity of frequency deviation, frequency control process. For large frequency deviations, emergency control loop is needed. When a micro grid turns into islanded mode, to remain stability, total generation of DGs must guarantee the total load. Otherwise, the micro grid starts to collapse. To avoid this, a control strategy, called emergency control, is applied. In this paper, an algorithm is designed for load shedding in isolated micro grid, also dynamical details of a MG on its response are considered.