The book demonstrates some research results of China's water quality criteria for toxic pollutants, such as heavy metals, PAHs and emerging pollutants etc. Water quality criteria (WQC) are scientific foundation for establishing water quality standards (WQSs). For a long time, the study of WQC in China is insufficient, so that almost all of the China's WQSs were developed according to foreign WQC. This book could provide valuable information for environmental management and revision of WQSs. It is written for researchers and graduate students in the field of environmental science and risk assessor for chemical and pollutants etc. Dr. Zhen-guang Yan is an Associate Professor at Chinese Research Academy of Environmental Sciences. Dr. Zhengtao Liu is a Professor at Chinese Research Academy of Environmental Sciences.