Indonesia is not one of the claimant states, but Chinese provocation through its fishing vessels which escorted by Chinese Coast Guard has been violating Indonesia Exclusive Economic Zone on South China Sea which is intersected with Nine Dashed Line (NDL). Until now, the synergy among Indonesian power instruments to defend Indonesia’s sovereign rights is still weak, thus the problem identification in this research is how the synergy of the instrument of competent forces in the Indonesian maritime domain to face Chinese Claims on South China Sea. Synergy analysis is seen from three aspects: perspective, policy, and Rules Of Engangement (ROE) applied to operational. This research uses qualitative method to explore research questions deeper, with Soft System Methodology analysis method to approach problems with the comparison between system thinking and real world in a structured way, and supported NVivo to execute the process of data triangulation. Research results show that maritime power instruments of Indonesia do not have a harmonious perspective on NDL yet. This study also shows that policy from policy makers and strategic derivatives from strategy makers of the Government of the Republic of Indonesia's have not been orchestrated, thus appropriate ROE at operational level to confront China's provocation of the South China Sea has not been formulated by adjusting authority with instrument capability. Overall, the study found that the synergy of Indonesian maritime power instruments need to be optimized to deal with Chinese Claims over the territory of Indonesian jurisdiction in the South China Sea.