Abstract: Dynamically mastering the quantity and value of reserve land assets holds significant importance for strengthening land management. Targeting City A within the Pearl River Delta urban agglomeration, this study proposed a method and corresponding procedure for reserve land asset inventory based on data from land surveys, reserve land records, and benchmark prices of construction land. Combined with the GeoScene, this study developed an inventory system for reserve land assets, enabling an automated inventory process. The results show that by using the proposed system, the automated inventory of reserve land assets improved both efficiency and overall accuracy. The total area of reserve land in City A was estimated to be 3 249.91 hm², with a total economic value of 34.827 829 4 billion yuan. Among these, plots with clearly defined planning conditions held an economic value of 33.384 586 8 billion yuan, while those without clearly defined planning conditions were valued at 1.443 242 6 billion yuan. The results of this study provide support for the compilation of natural resource balance sheets and the informatization of reserve land asset management.