Abstract: It is of great significance to better protect Macao's ancient buildings and stone wall trees, and to study the symbiotic relationship between them. This study conducted field surveys to comprehensively document the growth status, environment, and epiphytic location of stone wall trees in Macao. Through detailed observations and data collection from masonry trees in different areas, their distribution characteristics and biodiversity were analyzed. The research scope covered the Macao Peninsula and other related areas to ensure data comprehensiveness and representativeness. The results show that stone wall trees in Macao belong to 5 families, 6 genera, and 16 species. Among them, the Ficus plants have an occurrence frequency of 88.5%, making them the dominant group of stone wall trees in Macao. 84.36% of Macao's stone wall trees are located on the Macao Peninsula, and 82.3% of them grow on masonry walls, rocks and buildings. This indicates that stone wall trees are concentrated on the Macao Peninsula and have a significant symbiotic relationship with ancient buildings and natural stone walls. The result of this study provide a scientific basis for the conservation of stone wall trees and the protection of ancient buildings in Macao. It is recommended that attention should be paid to the ecological environment maintenance of stone wall trees while protecting ancient buildings to achieve a harmonious coexistence between the two.