During the period of the Republic of China，stimulated by the invasion of our islands and reefs，the exploitation of resources and the control of shipping routes by Western powers，the attention to maritime rights from government and the people is far greater than before. The new concept of sea power is displayed through the map carrier. In all aspect of cartographic subject，map scope and cartographic elements. Marine elements are enhanced on maps. Marine connectivity has also been more clearly demonstrated. Moreover，maps also express the changing process of safeguarding to maritime rights from passive to active. These maps played a positive role in the understanding of the territory of the sea and the maintenance of its integrity. But at the same time，especially in the map of the early Republic of China，the names of the islands in the South China Sea were mostly translated names from their English names，and the description of the sea territory was wrong. This limitation and its subsequent changes also showed that the cognition of sea power at that time was not perfect，which was still undergoing gradual changes and shaping.