Nitrosamines (NAs), are one class of emerging disinfection by-products in water. This paper summarized the sources, concentrations and the standard limit, the formation mechanism, the analysis and detection techniques, the control and removal methods of NAs. With the emphasis on the disinfection of drinking water and the promotion of sewage disinfection, it was suggested that it should be necessary in increasing the survery of NAs levels in a wide range of water and investigateing the precursors of NAs formation in complex sewage systems, and then optimizing and improving disinfection technologies to reduce the formation of NAs and establish accurate and reliable detection methods of NAs in complex water samples.