Abstract: The development and protection of uninhabited islands have become one of the hotspots for land and ocean sustainability in China nowadays. Land suitability evaluation is critical for designing optimization schemes of development and protection in uninhabited islands. In this study, Dayu island in Pingtan was taken as an example, spatial analysis function in GIS and analytic hierarchy process method were used to assess the dynamic changes of land development suitability during pre- (2014) and post- periods (2019). Results showed that the developed areas in 2019 only accounted for 43.8% of the proportion of suitable development zones identified in 2014, inferring that spatial allocation of development needs to be improved. Compared with the suitability evaluation results before and after development, the suitable development zone basically remains unchanged, but the unsuitable development zone changed to restricted development zone, indicating that the development potentials tend to increase over time. The study can provide helpful insights into spatial allocation and utility for Dayu island, as well as the other similar uninhabited islands in China.