A novel and simple fluorescence probe L ((E)-4-(1-(dimethylamino)naphthalene-5-sulfonamido)-N′-((2-hydroxynaphthalen-1-yl)methylene)benzohydrazide) for detection of Cr3+ was prepared by the introduction of dansyl sulfonamide fluorescent group and 2-hydroxy-1-naphthalaldehyde coordination group to p-aminobenzoic acid with chemical derivatization method. The structure of the probe L was investigated by 1H NMR, ESI-MS and FT-IR. The effect of probe L for recognition of Cr3+ was studied by fluorescence spectroscopy. The results show that the probe L shows a double peak at 473 nm (2-hydroxy-1-naphthaldehyde) and 514 nm (dansyl sulfonamide) when the excitation wavelength is 350 nm. After the addition of Cr3+ to the probe L, 2-hydroxy-1-naphthaldehyde was bonded to Cr3+, and the emission peak of dansylamine was red shifted to 540 nm (dansylamine characteristic peak). The intensity of fluorescence was increased by five times and the fluorescence quantum yield Φ was up to 028. The background fluorescence of the probe L has no effect on the recognition of Cr3+. The recognition process is presumed to be caused by the CHEF effect combined with PET (photoinduced electron transfer) mechanism. When the other metal ions were added, such as Na+, K+, Li+, Ca2+, Zn2+, Mn2+, Co2+, Cu2+, Cd2+, Hg2+, Pb2+, Ag+, the fluorescence intensity was not enhanced at 540 nm, indicating that the probe L had a high specific selectivity for Cr3+. A 1∶1 complexation stoichiometry for the binding mode of Cr3+ with L was confirmed by the model of the Job’s plot and ESI-MS result. The detection limit of L for Cr3+ was up to 40×10-6 mol·L-1.