Abstract: A method for the determination of arsenic, antimony and bismuth in geochemical samples by hydride generation-double channel atomic fluorescence spectrometry (AFS) was developed. The determination conditions were optimized through a series of experiments. The negative high voltage/lamp current of AFS instrument for determination of arsenic, antimony and bismuth were 280 V/40 mA, 280 V/60 mA, 280 V/60 mA respectively. The dilution factor was reduced in a certain extent by adding solid powder of thiourea-ascorbic acid. Therefore, the sensitivity was improved. Under the optimized conditions, the detection limits and analytical accuracy for the elements were remarkably improved. The method has been applied to the determination of arsenic, antimony and bismuth in geochemical samples with advantages of high sensitivity, high accuracy, high efficiency and low cost.