CO 2 storage in deep saline aquifer is still at its infancy and not yet matured for large scale industrial development due to the considerable uncertainties that still exist regarding storage capacity and safety. At the same time, because this is an expensive process, so engineers wish to store as much CO 2 as possible within a particular saline formation. However, injecting huge amounts of CO 2 into the particular saline formation pose significant technical issue such as pressure build-up and CO 2 leakage. Therefore, in order to fully exploit it is potential, optimum injection strategies need to be investigated. In this paper we examine a realistic model of deep saline aquifer and conduct optimization study on some simulation parameters by applying multi-objective particle swarm optimization algorithm (MOPSO) to Enhance CO 2 storage capacity and safety by, 1) Maximize total injected CO 2 , 2) Minimize pressure build-up in the center of the field and 3) Minimize CO 2 leakage at the edges of the aquifer.The result of this study shows that when changing the number of wells from 5 to 7 injectors the possible storage capacity for dome A is increased by 4%. However, the maximum CO 2 leakage did not reach the criterion of 0.1%/ year. The results also indicate that the MOPSO algorithm is promising in obtaining the desired objective to improve storage capacity significantly while reducing the pressure build-up and CO 2 migration.