Based on synergistic theory and the interaction regularity between urbanization and ecological environment, this paper puts forward the coordinative criteria and coordination degree model. The model includes efficacy function, coordination degree function and its parameter system, which the choice of parameter and determination of upper and lower limits are crucial for its available application. Take Jiangsu provinces as a case, an empirical study has been made with this model. The study shows that the coordinative criteria and model are univocal and easy to apply. They can effectively distinguish the different development levels of regional urbanization and eco-environment coordination, and are effective for coordinating regional urbanization development and eco-environment protection.