Abstract: A method for the determination of zinc, especially in complicated geological samples, by hydride generation atomic fluorescence spectrometry with alkaline system was established. Operation conditions for steam generation from alkaline solution and instrument parameters were investigated and optimized. Adding nickel ion enhanced zinc signals obviously. Under the optimized condition the detection limit of the method for zinc was 0.24 g/L with dynamic linear range of 0.5~800μg/L. In comparison with traditional acid system,new system provides higher sensitivity, wider linearity and less interference from coexistent elements. The method has been applied to the determination of zinc in national geological standard samples with satisfactory results. The recoveries of the method are 94.1%~ 101.2% with precision of less than 4.0％RSD (n＝6).