ABSTACTWith the widespread use of N2H4, it brings potential risk to human health and environmental safety because of its diverse toxicological functions. In order to determine N2H4 effectively in both environment and living systems, all kinds of fluorescence probes have been prepared for the specific response of N2H4 based on various mechanisms and different acceptor group for N2H4. This paper provides a review to bring more inspirations for the development of the fluorescent probes for N2H4.