Many countries are worried about reducing energy consumption and environmental pollution while increasing the productivity and efficiency of their industries. This study intends to contribute to the literature by proposing a non-radial DEA model with the slacks-based measure (SBM) to analyze the environmental efficiency of China's transportation sector. The results show that most of the provinces in China do not have an eco-efficient transportation industry. The environmental efficiency levels in most of the provinces are lower than 50% of the ideal or target level. Therefore, China's transportation industry is environmentally very inefficient. China can reduce a great deal of carbon emissions in each province ranging from at least 1.6 million TOEs in Qinghai and at most 33 million TOEs in Guangdong and Shanghai. (C) 2013 Elsevier Ltd. All rights reserved.