Abstract: The new and old ditches in Haikou City, Hainan Province are cultural landscapes with a history of twelve hundred years that were created by the modification and usage of the local environment and resources via the knowledge of farming. The preciousness of the 'living state' and the scientific nature of the ancient water conservancy project determine the inevitability of its protection. In accordance with the sequence of construction period, this study briefly describes the resource value of the old and new ditch cultural landscape systems. From the perspective of 'production-living-ecological' spatial optimization, it examines the distinctiveness of its spatial layout and suggest three new objectives for the optimization of the cultural landscape in the present: preserving the cultural landscape's integrity and authenticity, ensuring the inheritability of the core cultural content, and promoting the sustainable growth of society. Based on the aims, the present conservation issues are examined, and from this vantage point, general and graded conservation suggestions for the cultural landscape of the old and new ditches are proposed.