A novel colorimetric and off-on fluorescent chemosensor 2 was designed and synthesized, which showed reversible and highly selective and sensitive recognition toward Cr(3+) over other examined metal ions in aqueous solution. Upon addition of Cr(3+), the solution of chemosensor 2 resulted in a color change from colorless to obvious pink color, these significant changes in color could be used for naked-eye detection. Chemosensor 2 exhibited a stable response for Cr(3+) in the range 0-10 μM with a detection limit of 1 ppm. Furthermore, fluorescence imaging experiments of Cr(3+) ions in living MGC803 cells demonstrated its value of practical applications in biological systems.