A novel fluorescent sensor，8-(2-(octadecylamino)acetylamino)quinoline(AQZ-18)，was synthesized for sensing Zn2+.Two fluorescence peaks at 320 nm and 505 nm were observed in the solution of AQZ-18，non-ionic surfactant OP-10 and Zn2+.The shorter wavelength peak arised from autofluorescent OP-10 kept almost unchanged，while the longer wavelength peak produced by AQZ-18 increased gradually with increase of Zn2+ concentrations.Base on this， a new ratiometric method was established by measuring the ratio variations of fluorescence intensities in the two regions.The 1∶1 ground state complex between Zn2+ and AQZ-18 was formed，and the apparent association constant was obtained to be 1.1×106 L/mol.Some common metal ions had no obvious interference for AQZ-18 to detect Zn2+.The ratio of two fluorescence intensities presented a linear relationship with concentration of Zn2+ in the range of 0-1.1×10-5 mol/L(r2=0.996 2)，with a detection limit of 55 nmol/L.The method could be used for the determination of Zn2+ in water samples.