Cultivated reserved land resources are pivotal for achieving food security and sustainable agricultural development. However, existing research on these resources often grapples with issues such as the lack of current data and underutilization of available data. This study focuses on Haishu District in Ningbo City of China, an economically developed area, and uses the third national land survey data to identify potential agricultural and construction lands suitable for conversion to cultivation. Through the application of the limiting factor method and the Analytic Hierarchy Process (AHP), the results indicate that the potentials of reserved cultivated land and the reclamation potential of construction land in Haishu District are estimated at 503.07 and 1527.50 ha, respectively. These lands are primarily rated as generally suitable and marginally suitable for agriculture, suggesting a moderate overall quality of reserved cultivated resources. This study emphasizes the practice of surveying reserved cultivated land, to boost effective land management and strategic development.