This paper applies the data envelopment analysis approach to contribute to the debate on the environmental performance of China's manufacturing sector. Regional and periodic differences in environmental efficiency, environmental quantity and environmental change indexes in China's manufacturing sector are examined for the period between 1998 and 2002. Within the framework of data envelopment analysis and distance functions, environmental quantity and environmental change indexes are measured as variants of the Malmquist quantity index. The overall environmental efficiency of China's manufacturing sector is very low, indicating substantial potential to reduce pollution emissions in China's manufacturing industries. The results and implications of this study can provide helpful information to improve the environmental performance of China's manufacturing sector.