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Cyclooxygenase-2 (COX-2) has been used as an excellent traceable biomarker,and exists maximally in Golgi apparatus (Cancer cells).Celecoxib (CCB) is a selective inhibitor for COX-2,and has been used as one of non-steroidal anti-inflammatory drug.Herein we report the conjugation of nile blue (NB) with CCB via a six-carbon linkage to form a fluorescence probe NB-C6-CCB for the detection of COX-2.NB-C6-CCB displays strong fluorescence with the emission peak centered at near-infrared wavelength (700 nm) in tumor cells or tumor tissues with high expression of COX-2.Importantly,NB-C6-CCB can discriminate cancer cells (MCF-7) fluorescence intensity from normal ones (COS-7) in the co-culture medium under confocal microscope.Subcellular localization of the NBC6-CCB preferentially points to the Golgi apparatus and increases the fluorescent intensity.The competitive analysis (with CCB) and Native-PAGE analysis confirmed that NB-C6-CCB shows selective binding affinity towards COX-2 enzyme.Competitive analysis with CCB (flow cytometry assay) revealed the fluorescence intensity fluctuation due to pretreatment of CCB with different concentrations,indicating that the NB-C6-CCB is a precise or sensitive probe for the COX-2.Tumor tissue (depth:500 μm),organs and mice imaging tests show excellent nearinfrared visualization,specific localization and identification of tumors.