In order to provide convenience for people who are not familiar with the local language, many cities in the world will place bilingual or even multilingual road signs in important places. Most of the place names in Chinese cities are translated from Chinese to English through transliteration or simple free translation. However, it is difficult to know the historical and cultural significance of place names only through English translation. Due to historical reasons, Chinese and Portuguese are the official languages of Macao. All the public places in Macao need to be equipped with Chinese-Portuguese bilingual road signs. Unlike other cities in China, Macao geographical names cannot easily be formulated or translated in Portuguese. The Chinese and Portuguese names in many places seem to be unrelated, expressing two completely different things. This semantic difference is the epitome of Macao's unique multiculturalism. Through the analysis of the semantic differences between Chinese and Portuguese names in Macao, this paper summarizes the naming rules of Macao place names and traces back to their historical and cultural significance.