Developing highly sensitive and selective methods for Cu 2+ detection in living systems is of great significance in clinical copper-related disease diagnosis. In this work, a near infrared (NIR) fluorescent probe, CySBH, with a salicylaldehyde benzoyl hydrazone group as a selective and sensitive receptor for Cu 2+ was designed and synthesized. The specific coordination of the salicylaldehyde benzoyl hydrazone group in CySBH with Cu 2+ can induce a distinct quench of the fluorescence intensity, allowing for real-time tracking of Cu 2+ . We have demonstrated that CySBH could rapidly recognize Cu 2+ with good selectivity and high sensitivity. Moreover, on the basis of low cell cytotoxicity, the probe was used to visualize Cu 2+ in two cell lines by fluorescence imaging. Furthermore, CySBH can also be used to monitor Cu 2+ in vivo due to its NIR emission properties. These overall results illustrate that the NIR fluorescent probe CySBH provides a novel approach for the selective and sensitive monitoring of Cu 2+ in living systems. A near infrared fluorescent probe utilizing the salicylaldehyde benzoyl hydrazone group as the Cu 2+ receptor was developed and used to selectively and sensitively monitor Cu 2+ in living systems.