Ecological quality, efficiency, safety, and fairness are the core components of an eco-city. The expansion and contraction of urban ecological territories impacts eco-cities in all of these four components. The central distance of an ecological territory is an indicator that measures its expansion and contraction. As the central distance increases, measurable changes in the four components change either predictably, smoothly, or erratically, with fluctuation. Regulating the expansion and contraction of an urban ecological territory is an effective way to achieve a balanced eco-city.