The 21st century witnessed an upswing of new towns and ecocities, particularly in developing countries. China led this global phenomenon with more than 3,800 new towns built or under construction, hundreds of which also declared to grow toward ecocities, including the 19 National New Areas (NNAs) designated directly by the central government. However, given the complex agendas of eco-new-towns, these projects’ current influences on and potential contributions to their local environment and the global territory are still unclear. This dissertation argues that evaluating the “econess” of ecocities must be based on their contributions to the global ecosystem. It questions how the NNA policy impacted ecosystems in the past and explores how planners would/should design the NNAs’ landscape in the future. It first analyzes the NNAs’ ecological performance with two indicators of Ecosystem Service Value and Ecological Footprint on the national scale. Then two representative NNAs of Binhai (proposed in 2006) and Xiong’an (2017) are studied to depict how the ecological changes occurred and how planners’ ecological thinking evolved at the project level. Results suggest that the NNAs enhanced the local landscape evidently, but their influences on the regional and planetary ecosystems are still limited. In comparison to Binhai, a development-driven project of contradictory ecological plans and performance, Xiong’an’s deconcentration goal promoted positive progress in planning and practicing sustainability. However, new actions did not extend beyond improving the local ecosystem, and neither of the two projects held a holistic ecological approach or captured the nature of ecocities. The last exploratory section, a methodological revision of the existing spatial planning workflow, is included to support the future practice of eco-new-towns with digital technology. This dissertation contributes to policymakers, scholars, and planning practitioners by raising a planetary ecological perspective and proposing a scenario modeling method. With this perspective and method, a transformation from Industrial Civilization to Ecological Civilization is envisioned, not limited to the NNAs and China, but for the benefit of all human society.