This paper applies the pressure-state-response (PSR) model to establish environmental quality indices for 30 administrative regions in China from 2003 to 2011 and employs panel data analysis to study the relationships among the urbanization rate, economic development and environmental change. The results reveal a remarkable inverted-U-shaped relationship between the urbanization rate and changes in regional environmental quality; the "turning point" generally appears near an urbanization rate of 60%. In addition, the degree and mode of economic development have significant, but anisotropic effects on the regional environment. Generally, at a higher degree of economic development, the environment will tend to improve, but an extensive economic growth program that simply aims to increase GDP has a clear negative impact on the environment. Overall, the results of this paper not only further confirm the "environmental Kuznets curve hypothesis", but also expand it in a manner. The analysis in this paper implies that the inverted-U-shaped evolving relationship between environmental quality and economic growth (urbanization) is universally applicable.