Abstract: The testing materials are dissolved in hydrochloric acid and nitric acid. Thiourea and ascorbic acid are added to the solution to reduce pentavalent arsenic to trivalent arsenic. Arsenic reacts with potassium borohydride and hydrochloric acid and generates arsine in the hydride generator using 2% hydrochloric acid as the carrier and 1% sodium borohydride containing 0.5% potassium hydroxide as the reducing agent. Meanwhile, mercury becomes vapor. Arsine and mercury vapor are directed into a quartz furnace atomizer to be atomized by argon. The fluorescence intensity of arsenic and mercury are measured by an atomic fluorescence spectrometer through the excitation of hollow cathode lamps. The relative standard deviation of arsenic is 0.0096% and the one of mercury is 0.00015%, and the accuracy is favorable. The pre-treatment of the method is rapid and the reagent consumption is less resulting in a simple process.