Macao is a tourist city with a dense population and has a shortage of natural resources. Almost all of the city's life-support systems thus depend on imports of external resources. During the past 20 years, Macao has experienced an economic boom accompanied by rapid social development, in which the gambling industry and related tourism services have become the main economic activity. This paper employs emergy flow analysis to investigate and characterize the evolution and development of Macao from 1983 to 2003. In addition, Macao has experienced six periods of land reclamation since 1866, supported by large-scale importation of sand and rocks from China. By simulating the emergy trends using the STELLA dynamic modeling software, we predicted the evolution of Macao's development and trends in the coming 20 years. In 2025, the city's economy is estimated to be 15 times its current size as a result of Macao's territorial expansion. The exported emergy will increase slowly and then stabilize, the population will reach 593185, and the area covered by Macao will expand to 38.91km2.